Showing 1–50 of 338 results for author: Zhu, Z

Ripple Signatures of Majorana Hybridization across a Topological Quantum Quench

Authors: Xin-Xin Wang, Jin-Xin Li, Ya-Wen Tang, Lu Qin, Zun-Lue Zhu, Wu-Ming Liu, Liang-Liang Wang, Xing-Dong Zhao

Abstract: The crossover between topology and nonequilibrium dynamics has emerged as a rich frontier, in which quantum systems can exhibit unique dynamical phenomena that lie beyond the reach of equilibrium. Of particular interest are quench dynamics across topological phase, as it may reveal the information about the underlying Majorana zero-energy states. Here, we investigate the fate of Majorana boundary… ▽ More The crossover between topology and nonequilibrium dynamics has emerged as a rich frontier, in which quantum systems can exhibit unique dynamical phenomena that lie beyond the reach of equilibrium. Of particular interest are quench dynamics across topological phase, as it may reveal the information about the underlying Majorana zero-energy states. Here, we investigate the fate of Majorana boundary modes in a quenched fermionic superfluid using self-consistent time-dependent Bogoliubov-de Gennes theory. For quantum quenches within the topological regime, Majorana boundary modes survive but undergo coherent boundary oscillations arising from the nonadiabatic deformation of their wave functions. Furthermore, a pronounced ripple pattern appears in the post-quench density distribution following a sudden topology-changing quench. Here we identify that these ripple structures originates from the coherent hybridization and interference of the initially separated Majorana boundary states. Our findings establish nonequilibrium boundary dynamics as a new approach for probing Majorana physics, which is complementary to conventional equilibrium measurements. △ Less

Submitted 10 August, 2026; originally announced August 2026.

Time-Reversal-Invariant Altermagnetic Acoustic Crystals

Authors: Tianzhi Xia, Han-Rong Xia, Jinglin Liu, Xiying Fan, Zebin Zhu, Zhen Gao

Abstract: Altermagnets have emerged as a new class of magnetic materials that combine spin-split electronic bands with zero net magnetization. Extending this paradigm to classical-wave systems has, however, been fundamentally challenging because conventional realizations require broken time-reversal symmetry (TRS). Here, we overcome this limitation by introducing two pseudospin degrees of freedom and constr… ▽ More Altermagnets have emerged as a new class of magnetic materials that combine spin-split electronic bands with zero net magnetization. Extending this paradigm to classical-wave systems has, however, been fundamentally challenging because conventional realizations require broken time-reversal symmetry (TRS). Here, we overcome this limitation by introducing two pseudospin degrees of freedom and constructing a pseudo-time-reversal operator that faithfully reproduces the action of its physical counterpart while preserving actual TRS. Building on this framework, we theoretically propose and experimentally realize the first time-reversal-invariant altermagnetic acoustic crystal. Acoustic measurements directly reveal pseudospin-dependent band splitting--a defining hallmark of altermagnetism--under strictly TRS-preserving conditions. Moreover, the altermagnetic acoustic crystal exhibits sublattice-pseudospin locking, enabling flexible control over acoustic pseudospin splitting and filtering. Our work establishes acoustic crystals as a versatile platform for exploring altermagnetic physics and opens new avenues for spin-inspired wave manipulation in nonmagnetic devices. △ Less

Submitted 9 August, 2026; originally announced August 2026.

Comments: 12pages, 4 figures

A subsurface array of photonic crystal slabs produces green stripes in a scarab beetle

Authors: Laura Ospina-Rozo, Nicola S. Kubzdela, Zezheng Zhu, James A. Hutchison, Mia Wansbrough, Nanfang Yu, Devi Stuart-Fox

Abstract: Vivid colours in nature often arise from photonic nanostructures that have inspired diverse technologies. Yet most known examples fall within a limited set of structural themes. Here, we describe a biologically and optically novel structure in the bright green, violin-shaped stripes of the fiddler beetle Eupoecila australasiae. The green colour is produced by a composite, hierarchical structure co… ▽ More Vivid colours in nature often arise from photonic nanostructures that have inspired diverse technologies. Yet most known examples fall within a limited set of structural themes. Here, we describe a biologically and optically novel structure in the bright green, violin-shaped stripes of the fiddler beetle Eupoecila australasiae. The green colour is produced by a composite, hierarchical structure comprising dense arrays of microscopic, fin-like elements located beneath the cuticle. Each vertical fin, patterned with complementary lattices of nanospheres and indentations, can be approximated by two photonic crystal slabs mounted on a solid central core. Optical modelling shows that the fins are strongly iridescent, reflecting light with longer wavelengths near the normal and light with shorter wavelengths at oblique angles. However, disorder in fin orientation and filtering by the overlying cuticle converts the opaline cyan appearance of the fins into the bright diffuse green seen externally. Our work expands the known diversity of biological photonic nanostructures and offers new inspiration for biomimetic designs. △ Less

Submitted 18 August, 2026; v1 submitted 3 August, 2026; originally announced August 2026.

Comments: 22 pages, 5 figures. Preprint

Laser-intensity-spike-dominated hot electron generation from two-plasmon decay instability driven by moderate-bandwidth pulses

Authors: C. Yao, Z. H. Cai, X. Wang, X. C. Wang, H. R. Yin, Z. A. Zhu, C. W. Lian, Y. Ji, X. Jiang, S. M. Xu, Y. Y. Yao, L. Y. Yang, J. N. Zhang, D. Meng, T. Peng, H. Wen, C. Z. Xiao, K. Y. Meng, J. Li, R. Yan, P. Yuan, Z. Zhang, L. Hao, Q. Jia, W. Feng , et al. (12 additional authors not shown)

Abstract: Our direct-drive-relevant experiments on the low-coherence Kunwu laser facility identify two-plasmon decay (TPD) as the primary source of hot electrons, and demonstrate for the first time that broadband laser pulses enhance TPD. Using particle-in-cell simulations, we attribute this TPD enhancement and the consequent hot electron production to stochastic intensity spikes inherent in broadband laser… ▽ More Our direct-drive-relevant experiments on the low-coherence Kunwu laser facility identify two-plasmon decay (TPD) as the primary source of hot electrons, and demonstrate for the first time that broadband laser pulses enhance TPD. Using particle-in-cell simulations, we attribute this TPD enhancement and the consequent hot electron production to stochastic intensity spikes inherent in broadband laser fields, robust in both weakly- and strongly-driven regimes. These findings suggest that mitigating hot electron generation requires suppressing these intensity spikes. △ Less

Submitted 24 June, 2026; originally announced June 2026.

Observation of fractality-induced topology in photonic crystals

Authors: Bei Yan, Yingfeng Qi, Xiang Xi, Linyun Yang, Yan Meng, Zhen-Xiao Zhu, Jing-Ming Chen, Ziyao Wang, Zhen Gao

Abstract: Fractal topology--achieved by integrating nontrivial topology into fractal geometries with self-similarity and non-integer dimensions--has opened new avenues for exploring topological phases of matter. Recent theoretical advances revealed a counterintuitive fractal topology: fractality itself can induce nontrivial topology in an otherwise trivial system. Here, we report the first experimental obse… ▽ More Fractal topology--achieved by integrating nontrivial topology into fractal geometries with self-similarity and non-integer dimensions--has opened new avenues for exploring topological phases of matter. Recent theoretical advances revealed a counterintuitive fractal topology: fractality itself can induce nontrivial topology in an otherwise trivial system. Here, we report the first experimental observation of fractality-induced topology in a tight-binding-like photonic crystal, without relying on traditional driving mechanisms such as magnetic fields, staggered hopping, or spin-orbit coupling. We demonstrate that fractality alone is sufficient to lift the degeneracy of Kagome lattice band structure and induce topological corner states within the bandgap of the resulting fractal Kagome photonic crystal, which is a photonic higher-order topological insulator. This work experimentally reveals a novel mechanism for realizing nontrivial topological states, expanding both the fundamental frontier and potential application of topological physics. △ Less

Submitted 23 June, 2026; originally announced June 2026.

Digital programming of spin correlations in a fermionic lattice quantum simulator

Authors: Yann Kiefer, Lars Fischer, Zijie Zhu, Konrad Viebahn, Tilman Esslinger

Abstract: Analog quantum simulation provides a highly controlled platform to study diverse quantum many-body phenomena. However, current methods for state initialisation are limited to thermal ensembles or uncorrelated product states. Here we present a hybrid approach that complements analog preparation with a digital quantum-gate protocol. This approach enables the engineering of target states with specifi… ▽ More Analog quantum simulation provides a highly controlled platform to study diverse quantum many-body phenomena. However, current methods for state initialisation are limited to thermal ensembles or uncorrelated product states. Here we present a hybrid approach that complements analog preparation with a digital quantum-gate protocol. This approach enables the engineering of target states with specific, long-range spin-correlations from the same initial resource state. By applying collisional gates to adiabatically prepared and filtered four-fermion singlet chains, we program diverse spin-correlation patterns, including that of a Heisenberg chain. We measure the spin correlations using a sequence of quantum gates followed by singlet-pair measurements. Our method paves the way to the targeted preparation of strongly correlated states of matter. △ Less

Submitted 11 June, 2026; originally announced June 2026.

Limits of constant-parameter constitutive models for hydrogels under inertial cavitation

Authors: Tianyi Chu, Joseph Beckett, Zhiren Zhu, Jonathan B. Estrada, Spencer H. Bryngelson

Abstract: Mechanical characterization of soft materials at high strain rates is challenging due to their high compliance, nonlinear viscoelastic behavior, and potentially history-dependent responses. Inertial microcavitation rheometry (IMR) addresses this challenge by coupling laser-induced cavitation (LIC) experiments with numerical simulations of bubble dynamics models to infer constitutive models and mat… ▽ More Mechanical characterization of soft materials at high strain rates is challenging due to their high compliance, nonlinear viscoelastic behavior, and potentially history-dependent responses. Inertial microcavitation rheometry (IMR) addresses this challenge by coupling laser-induced cavitation (LIC) experiments with numerical simulations of bubble dynamics models to infer constitutive models and material parameters. Both IMR and its variants infer parameters that depend on the chosen fitting window, which suggests that a constant-parameter constitutive model is insufficient to describe the full cavitation event. We use this window dependence to identify when the constant-parameter assumption fails, rather than to report a single effective parameter set. The constitutive parameters are estimated over moving, overlapping windows using a modified iterative ensemble Kalman smoother with multiple data assimilation (MIEnKS-MDA). Within the neo-Hookean Kelvin--Voigt (NHKV) constitutive model, we obtain time-resolved estimates of the constitutive response in polyacrylamide (PAAm) hydrogels with different crosslinker concentrations. The inferred shear modulus and viscosity generally decrease and then plateau during cavitation, while exhibiting relatively weak temperature sensitivity. For gelatin gels, by contrast, the inferred property evolution shows a pronounced temperature dependence, with distinct trends at low and high temperatures. Moreover, both the apparent shear modulus and viscosity exhibit significant variations during the first two bubble collapses. These results show that time-resolved parameter estimation within the prescribed NHKV constitutive structure can diagnose where the constant-parameter model assumption falls short during cavitation, thereby guiding the development of improved physics-based models of complex bubble--material interactions. △ Less

Submitted 11 June, 2026; originally announced June 2026.

Sub-8-nm resolution AKB-mirror-based hard X-ray ptychography via generalized Wirtinger projections

Authors: Jie Dong, Liang Zhou, Zhongzhu Zhu, Han Xu, Aiyu Zhou, Xuan Wang, Shuo Wang, Xiao Li, Yuhui Dong

Abstract: Hard X-ray ptychography has become increasingly essential in both the life and physical sciences. However, pushing resolution down to a few nanometres often requires highly customized, chromatic diffractive or refractive X-ray nanofocusing optics, significantly limiting the practical broadband energy-scan applications. Here, we present the first known hard X-ray ptychographic imaging with a half-p… ▽ More Hard X-ray ptychography has become increasingly essential in both the life and physical sciences. However, pushing resolution down to a few nanometres often requires highly customized, chromatic diffractive or refractive X-ray nanofocusing optics, significantly limiting the practical broadband energy-scan applications. Here, we present the first known hard X-ray ptychographic imaging with a half-pitch resolution below 8 nm using total-reflection Advanced Kirkpatrick-Baez (AKB) mirror nanofocusing optics at the high energy photon source (HEPS), with clear potential for further extension. Despite leveraging the benefits of enhanced instrumentation, such as the high coherent flux of 4th-generation diffraction-limited storage rings (DLSR), state-of-the-art beamline X-ray optics and detectors, this is made possible by developing a reconstruction algorithm termed Generalized Wirtinger Projections (GWP). We derive the theory of GWP and experimentally demonstrate its capability for improved partial-coherence reconstruction and enhanced spatial resolution over conventional methods through imaging experiments on a Siemens star test chart at 12.4 keV. GWP provides a highly compact framework for jointly accounting for multiple coupled uncertainties that degrade resolution, enabling straightforward extension to other imaging modalities, such as burst ptychography, while delivering nearly an order-of-magnitude improvement in GPU memory efficiency. Furthermore, the ability to combine nanometre-scale spatial resolution with the inherently achromatic nanofocusing optics demonstrated in this work potentially opens new opportunities for in situ or operando broadband, energy-scan 3D spectroscopic imaging with element- or chemical-state specificity in complex environments at the nanoscale, holding significant promise for a wide range of applications from electronics and energy science to neuroscience. △ Less

Submitted 11 June, 2026; originally announced June 2026.

A Framework to Model Stellar Irradiated Disks with Frequency-dependent Absorption and Scattering Opacities in Athena++

Authors: Stanley A. Baronett, Yan-Fei Jiang, Zhaohuan Zhu, Shangjia Zhang, Philip J. Armitage

Abstract: The frequency dependence of opacity is crucial for determining the thermal structure of protoplanetary disks, which in turn influences disk dynamics and planet formation. Yet many disk models adopt simplified thermodynamics, and common radiation-hydrodynamic approaches often use gray opacities, ignore scattering, and yield inaccurate results in regions with intermediate optical depth. We present a… ▽ More The frequency dependence of opacity is crucial for determining the thermal structure of protoplanetary disks, which in turn influences disk dynamics and planet formation. Yet many disk models adopt simplified thermodynamics, and common radiation-hydrodynamic approaches often use gray opacities, ignore scattering, and yield inaccurate results in regions with intermediate optical depth. We present a comprehensive framework that models stellar irradiation with frequency-dependent absorption and scattering across all optical depths using the Athena++ finite-volume code, extended with multigroup radiation transport and newly implemented radial rays to more accurately represent the stellar flux. To calibrate this framework, we focus exclusively on hydrostatic disk models, allowing us to isolate radiative effects and evaluate the method without additional dynamical complexity. Because dust opacity increases strongly with frequency, ultraviolet stellar irradiation heats the tenuous disk atmosphere while the optically thick midplane remains cooler. This vertical temperature gradient is captured more accurately when more frequency bands are used or when scattering is included. Our hydrostatic models achieve equilibrium temperatures that differ from Monte Carlo radiative-transfer benchmarks on average by 2--5% with 64 frequency bands and 7--11% with 3 bands. Reducing the number of bands lowers computational cost by at least an order of magnitude while increasing the maximum possible temperature deviation only from 8% to 19%. This calibration demonstrates the accuracy and efficiency of the framework and provides a solid foundation for future self-consistent studies of irradiated protoplanetary disks, including fully dynamical simulations and applications involving chemical processes and time-dependent stellar luminosity. △ Less

Submitted 15 June, 2026; v1 submitted 7 June, 2026; originally announced June 2026.

Comments: 32 pages, 17 figures, ApJ revision under review; for associated repository, see https://github.com/sabaronett/irrad_disk/tree/main

A Mid-Infrared Platform Based on Strontium Tweezer Arrays

Authors: Aaron Holman, Ximo Sun, Bojeong Seo, Joshua Corn, Zezheng Zhu, Yuan Xu, Jiahao Wu, Nanfang Yu, Dmytro Filin, Marianna Safronova, Sebastian Will

Abstract: Subwavelength atomic tweezer arrays, in which atoms can be positioned at distances smaller than their emission wavelength, have been proposed as a versatile platform to study collective emission phenomena, such as superradiance and subradiance. Experimentally, the realization of such arrays has been a challenge as typical emission wavelengths in the visible or near-infrared are short compared to t… ▽ More Subwavelength atomic tweezer arrays, in which atoms can be positioned at distances smaller than their emission wavelength, have been proposed as a versatile platform to study collective emission phenomena, such as superradiance and subradiance. Experimentally, the realization of such arrays has been a challenge as typical emission wavelengths in the visible or near-infrared are short compared to typical tweezer spacings in the micrometer range. Here, we use $^{88}$Sr atoms in optical tweezer arrays to access a mid-infrared transition at 2,923 nm ($5s5p\:^{3}P_{2} \rightarrow\, 5s4d\:^{3}D_{3}$). We identify a magic trapping wavelength at 597.14(3) nm and demonstrate single-atom preparation and imaging with high fidelity. In addition, using 2,923 nm light, we demonstrate resolved-sideband cooling of tweezer-trapped strontium. Beyond enabling studies of collective emission phenomena in flexible arrangements of atoms, our platform opens novel opportunities for dipolar many-body physics and enhanced control over Rydberg dynamics and the strontium fine-structure qubit. △ Less

Submitted 1 June, 2026; originally announced June 2026.

Comments: 10 pages, 7 main figures, 3 appendix figures

Orbital Altermagnetic Photonic Crystal

Authors: Sichang Qiu, Huichang Li, Yan Meng, Xiang Xi, Zebin Zhu, Ce Shang, Zhen Gao, Tie Jun Cui, Shuo Liu

Abstract: Altermagnetism features momentum-dependent spin splitting without net magnetization, extending spintronics beyond conventional ferromagnetism and antiferromagnetism. However, the photonic realization of altermagnetism has remained a formidable challenge due to the fundamental differences between fermionic electrons and bosonic photons. Here, we report the first experimental realization of an orbit… ▽ More Altermagnetism features momentum-dependent spin splitting without net magnetization, extending spintronics beyond conventional ferromagnetism and antiferromagnetism. However, the photonic realization of altermagnetism has remained a formidable challenge due to the fundamental differences between fermionic electrons and bosonic photons. Here, we report the first experimental realization of an orbital altermagnetic photonic crystal, based on an antiunitary $C_{4z}\mathcal{T}$ symmetry enforced correspondence between a local $p$-orbital $σ/π$ doublet and crystal momentum. We experimentally demonstrate that the resulting system exhibits momentum-dependent spin splitting with alternating pseudospin polarization and a $d_{xy}$-wave form factor, as confirmed by measured band structures and iso-frequency contours. Moreover, we show that the orbital altermagnetic photonic crystal supports unique pseudospin-selective transport of electromagnetic waves, including photonic pseudospin splitting and pseudospin filtering. Our results extend the field of alternagnetism to photonic systems, opening a new avenue for designing spinphotonic devices. △ Less

Submitted 27 May, 2026; originally announced May 2026.

Comments: 9 pages, 4 figures

Pulsed thermal annealing enables switching of chiral antiferromagnetic order with a sub-millitesla field in Mn$_3$Sn

Authors: Xiaokang Li, Jing Zhang, Xiaodong Guo, Zengwei Zhu

Abstract: The manipulation of antiferromagnetic (AFM) order is a central theme in modern spintronics. In this work, we achieve reliable switching of the chiral AFM state in the Weyl antiferromagnet Mn$_3$Sn using a heat pulse combined with a very small magnetic field as small as 0.1 mT. By systematically measuring the anomalous Hall effect (AHE) in high-quality single crystals, we show that the field needed… ▽ More The manipulation of antiferromagnetic (AFM) order is a central theme in modern spintronics. In this work, we achieve reliable switching of the chiral AFM state in the Weyl antiferromagnet Mn$_3$Sn using a heat pulse combined with a very small magnetic field as small as 0.1 mT. By systematically measuring the anomalous Hall effect (AHE) in high-quality single crystals, we show that the field needed for switching decreases as the temperature approaches the Néel temperature $T_N$, and vanishes at $T_N$. Pulsed thermal annealing above $T_N$ followed by cooling in a tiny external field enables full and reproducible switching of the magnetic octupole order. Our results show that thermal softening (heating above $T_N$ to temporarily remove the magnetic anisotropy) is a key step that lowers the energy barrier to nearly zero. This allows an extremely weak directional field (like the effective field from spin-orbit torque in thin-film devices) to set the final magnetic state during cooling. We also provide a simple model to estimate the temperature rise in nanoscale devices under current pulses, giving practical guidance for device design. This work highlights that thermal effects are not a side issue but an important partner to spin torques, and suggests that future work should take both into account. △ Less

Submitted 21 May, 2026; originally announced May 2026.

Comments: 7 pages, 3 figures

Thermal Deformation Reduction in High-Power Interferometry with Higher-Order Laser Modes

Authors: Liu Tao, Yuhang Zhao, Zong-Hong Zhu, Paul Fulda

Abstract: Test-mass thermal noise is a limiting noise source for current and next-generation ground-based gravitational-wave observatories. Uniform-intensity higher-order laser beams, including Laguerre-Gaussian (LG) and Hermite-Gaussian (HG) modes, have been proposed as alternatives to the fundamental Gaussian beam due to their thermal-noise advantages. As interferometer power increases toward the megawatt… ▽ More Test-mass thermal noise is a limiting noise source for current and next-generation ground-based gravitational-wave observatories. Uniform-intensity higher-order laser beams, including Laguerre-Gaussian (LG) and Hermite-Gaussian (HG) modes, have been proposed as alternatives to the fundamental Gaussian beam due to their thermal-noise advantages. As interferometer power increases toward the megawatt regime, thermal aberrations from absorption in the test-mass coatings become increasingly significant. In this work, we quantify the robustness of higher-order modes against absorption-induced thermal deformation. We show that, under identical operating conditions, higher-order modes produce substantially more uniform thermal distortions than the fundamental mode, requiring significantly less thermal compensation power. The optimal curvature correction is reduced to 33% for the LG$_{2,2}$ mode and 24% for the HG$_{3,3}$ mode relative to the fundamental mode. We further show that the residual thermal deformation of higher-order modes results in lower optical loss, larger cavity power buildup, and improved modal purity in an aLIGO-like cavity. In addition, astigmatism compensation further enhances the intracavity purity of HG modes under self-heating-induced deformation. These results demonstrate that higher-order modes not only mitigate thermal noise but also intrinsically reduce beam self-heating effects, making them promising candidates for future high-power gravitational-wave interferometers. △ Less

Submitted 11 May, 2026; originally announced May 2026.

Comments: 14 pages, 9 figures

Journal ref: Phys. Rev. D 114, 022004 (2026)

OpenMRF: A Modular, Vendor-Neutral Open-Source Framework for Reproducible Magnetic Resonance Fingerprinting using Pulseq

Authors: Tom Griesler, Jannik Stebani, Sydney Kaplan, Ivaylo Angelov, Petra Albert, Martin Blaimer, Tobias Wech, Xiang Wang, Qingping Chen, Maxim Zaitsev, Zhibo Zhu, Qi Liu, Peter Martin, Jon-Fredrik Nielsen, Jesse I Hamilton, Peter Nordbeck, Nicole Seiberlich, Maximilian Gram

Abstract: Purpose: Widespread adoption and methodological advancement of Magnetic Resonance Fingerprinting (MRF) are limited by the lack of unified, reproducible implementation frameworks and fragmented open-source tools. To address these barriers, we introduce OpenMRF - a comprehensive Pulseq-based solution - designed to enable consistent, reproducible, and transferable MRF research across vendors, sites,… ▽ More Purpose: Widespread adoption and methodological advancement of Magnetic Resonance Fingerprinting (MRF) are limited by the lack of unified, reproducible implementation frameworks and fragmented open-source tools. To address these barriers, we introduce OpenMRF - a comprehensive Pulseq-based solution - designed to enable consistent, reproducible, and transferable MRF research across vendors, sites, and field strengths. Methods: OpenMRF integrates modular Pulseq-based sequence design, Bloch-simulation-based dictionary creation directly from .seq files, and iterative low-rank subspace reconstruction. The framework was evaluated through digital phantom simulations, a multi-site ISMRM/NIST phantom study on Siemens MRI systems at 0.55 T, 1.5 T, and 3 T as well as GE and United Imaging 3 T platforms, and representative in vivo acquisitions in the liver (0.55 T), myocardium (1.5 T), and brain (3 T). Results: Simulations demonstrated high mapping accuracy in an ISMRM/NIST-like digital phantom, with low-rank reconstruction yielding deviations of 0.03+/-0.32 % (T1) and 0.12+/-1.94 % (T2). The multi-site phantom study yielded relaxation times consistent with reference values at all field strengths, with mean deviations of -0.1+/-2.9 % (T1), -1.5+/-8.7 % (T2), and -4.0+/-7.2 % (T1rho). In vivo acquisitions produced high-quality parameter maps across platforms and field strengths. Conclusion: OpenMRF provides a robust, open-source, end-to-end Pulseq-based solution for MRF that enables reproducible sequence implementation, physics-accurate dictionary simulation, and advanced reconstruction across vendors and field strengths. By providing a unified platform for method development, comparison, and multi-site validation, OpenMRF aims to accelerate reproducible and harmonized quantitative MRI research within the community. △ Less

Submitted 24 April, 2026; originally announced April 2026.

Reconfigurable ultrafast perovskite polariton logic gates via nonlinear dynamics

Authors: Yuyang Zhang, Zhuoya Zhu, Xin Zeng, Shuai Zhang, Xinyi Deng, Tian Lan, Changhai Zhu, Kwok Kwan Tang, Qinglin Jia, Yuexing Xia, Yiyang Gong, Wenna Du, Feng Li, Rui Su, Xuekai Ma, Xinfeng Liu, Qing Zhang

Abstract: Exciton-polaritons provide a great platform for developing ultrafast all-optical logic gates for quantum and optical chips. However, progress toward practical polariton logic remains limited due to incomplete logical functionality on a single device. Herein, we present a single-device perovskite polariton platform enabling reconfigurable, ultrafast logic gates with functional completeness. The dev… ▽ More Exciton-polaritons provide a great platform for developing ultrafast all-optical logic gates for quantum and optical chips. However, progress toward practical polariton logic remains limited due to incomplete logical functionality on a single device. Herein, we present a single-device perovskite polariton platform enabling reconfigurable, ultrafast logic gates with functional completeness. The device consists of an optically trapped perovskite microwire, generating well-controlled non-equilibrium polariton condensation states for multiple logic operation channels. By tailoring the power of signal and gate beams, the same device is programmed to execute three basic Boolean functions (AND,OR,and NOT) and a high-order XOR function with a high on/off ratio of 21 dB, and a fast response time 6.7 ps. The reconfigurability arises from the selective activation of different nonlinear responses of polariton condensates, including amplification, seeding state transitions, and nonlinear interaction. These results provide valuable insights for advancing exciton-polariton logic gates. △ Less

Submitted 23 April, 2026; originally announced April 2026.

Comments: 16 pages, 5 figures

Observation of full momentum bandgap in photonic time crystals

Authors: Bolun Huang, Zebin Zhu, Genrong Yu, Zhen Gao

Abstract: The hallmark feature of photonic time crystals (PTCs) is the momentum bandgap, yet opening such a gap is extremely challenging, as it demands strong and rapid temporal modulation of the material properties. Recent theoretical advances have shown that resonance effects can substantially expand the momentum bandgap, and even give rise to a full (infinite) momentum bandgap spanning the entire momentu… ▽ More The hallmark feature of photonic time crystals (PTCs) is the momentum bandgap, yet opening such a gap is extremely challenging, as it demands strong and rapid temporal modulation of the material properties. Recent theoretical advances have shown that resonance effects can substantially expand the momentum bandgap, and even give rise to a full (infinite) momentum bandgap spanning the entire momentum space. Despite these predictions, a full momentum bandgap has yet to be observed experimentally. Here, we report the first experimental observation of full momentum bandgaps in a microwave PTC. By enhancing the resonant effect, we demonstrate that the momentum bandgap can be drastically widened in a dynamically modulated microwave surface plasmon transmission-line metamaterial, leading to tighter spatiotemporal field confinement and greater robustness against temporal disorder. Remarkably, using a dynamically modulated microwave coupled resonator metamaterial characterized by coupled-resonator optical waveguide dispersion, we achieve a full momentum bandgap spanning the entire momentum space, thereby enabling arbitrary spatial localization and temporal amplification of microwave fields. Our findings establish a unified experimental framework for expanding momentum bandgaps up to an infinite extent with minimal requirements on modulation strength and speed, thus paving a viable route toward the first experimental realization of PTCs at optical frequencies. △ Less

Submitted 19 April, 2026; originally announced April 2026.

Differentiable hybrid force fields support scalable autonomous electrolyte discovery

Authors: Xintian Wang, Junmin Chen, Zhuoying Zhu, Peichen Zhong

Abstract: Autonomous electrolyte discovery demands a computational engine that satisfies a critical trilemma: it must be fast enough for high-throughput screening, accurate enough for quantitative property prediction, and calibratable enough for online refinement. Classical empirical force fields (FFs) are fast but rely on error cancellation, while standard machine learning interatomic potentials (MLIPs) ar… ▽ More Autonomous electrolyte discovery demands a computational engine that satisfies a critical trilemma: it must be fast enough for high-throughput screening, accurate enough for quantitative property prediction, and calibratable enough for online refinement. Classical empirical force fields (FFs) are fast but rely on error cancellation, while standard machine learning interatomic potentials (MLIPs) are computationally expensive. In this Perspective, we highlight that differentiable hybrid FFs resolve this trilemma by fusing physically motivated functional forms with neural-network short-range corrections. Grounded in Energy Decomposition Analysis (EDA), state-of-the-art models such as PhyNEO-Electrolyte and ByteFF-Pol achieve zero-shot generalization to bulk phases, delivering throughputs on the order of tens of ns/day (up to $\sim$50 ns/day, depending on model complexity) for 10,000-atom systems. Crucially, their physical skeletons provide a well-conditioned parameter space for differentiable molecular dynamics (dMD). This enables a dual-calibration paradigm: bottom-up \textit{ab initio} parameterization combined with top-down fine-tuning from macroscopic experimental observables. We propose that this architecture meets the requirements of a ``ChemRobot-ready'' digital twin by integrating physics-grounded simulation with experimentally calibratable refinement, thereby enabling closed-loop autonomous electrolyte discovery. △ Less

Submitted 5 June, 2026; v1 submitted 9 April, 2026; originally announced April 2026.

Local thermal probe in a one-dimensional chain: An efficient dissipaton-based approach

Authors: Hao-Yang Qi, Zi-Fan Zhu, Yao Wang, Rui-Xue Xu, YiJing Yan

Abstract: We study a system consisting of an infinite one-dimensional molecular chain and a locally coupled probe. Starting from the Hamiltonian of the chain-probe composite and the corresponding spectral densities, we evaluate the heat current between the probe and the chain. For this purpose, we develop a dissipaton-based quantum approach that is fully nonperturbative and non-Markovian. The dissipaton alg… ▽ More We study a system consisting of an infinite one-dimensional molecular chain and a locally coupled probe. Starting from the Hamiltonian of the chain-probe composite and the corresponding spectral densities, we evaluate the heat current between the probe and the chain. For this purpose, we develop a dissipaton-based quantum approach that is fully nonperturbative and non-Markovian. The dissipaton algebra yields a set of hierarchically coupled equations of motion for the dissipaton moments, with cross-tier connections in an iterative manner if higher-order chain-probe interactions are included. Numerical results demonstrate the effects of temperature, frequency, onsite energy modification and higher-order couplings on heat transport. This work provides a general framework for thermal transport and other properties in locally probed systems and can be straightforwardly extended to higher-dimensional materials and electronic transport problems with strong many-body effects. △ Less

Submitted 31 March, 2026; originally announced March 2026.

Comments: 11 pages, 5 figures

Closeby Habitable Exoplanet Survey (CHES). V. Planetary Parameters Derived from Angular Separation Variations

Authors: Dongjie Tan, Jianghui Ji, Chunhui Bao, Xiumin Huang, Guo Chen, Su Wang, Yao Dong, Jiacheng Liu, Zi Zhu, Haitao Li, Junbo Zhang, Liang Fang, Dong Li, Lei Deng

Abstract: The Closeby Habitable Exoplanet Survey (CHES) aims to achieve microarcsecond-level astrometry of about one hundred nearby FGK-type stars within 10 parsecs to detect Earth-like planets. Such precision exceeds the capability of absolute astrometry relying on Gaia catalogs, whose positional accuracy degrades over time due to error propagation from stellar motion and epoch offsets, limiting their use… ▽ More The Closeby Habitable Exoplanet Survey (CHES) aims to achieve microarcsecond-level astrometry of about one hundred nearby FGK-type stars within 10 parsecs to detect Earth-like planets. Such precision exceeds the capability of absolute astrometry relying on Gaia catalogs, whose positional accuracy degrades over time due to error propagation from stellar motion and epoch offsets, limiting their use in microarcsecond-level detection. Traditional relative astrometry depends on positional components along right ascension and declination, requiring precise knowledge of field rotation and satellite attitude, which introduces additional errors. To address this, we propose a new relative measurement model based solely on variations in the length of angular separation between the target and reference stars, independent of direction. The model incorporates effects such as proper motion, parallax, radial velocity, light aberration, gravitational lensing, and planetary perturbations, enabling reconstruction of planetary orbits and masses. This approach enhances measurement stability and precision, providing a framework that is not entirely dependent on the Gaia catalog and suitable for CHES and other future high-accuracy astrometric missions. △ Less

Submitted 29 March, 2026; originally announced March 2026.

Comments: 20 pages, 7 figures, accepted to Research in Astronomy and Astrophysics

Stable (2+1)-dimensional soliton and breather molecules in a cold Rydberg atomic gas

Authors: Lu Qin, Hairu Zhai, Lu Liu, Yingying Zhang, Zeyun Shi, Zunlue Zhu, Xingdong Zhao, Wuming Liu, Boris A. Malomed

Abstract: We investigate the formation of stable (2+1)-dimensional spatial-domain optical soliton molecules and breather molecules in a gas of Rydberg atoms, highlighting the role of the nonlocal nonlinearity, which is generated by the electromagnetically induced transparency in the Rydberg medium. The setting supports diverse species of large-size polygonal soliton molecules, including rectangular and obli… ▽ More We investigate the formation of stable (2+1)-dimensional spatial-domain optical soliton molecules and breather molecules in a gas of Rydberg atoms, highlighting the role of the nonlocal nonlinearity, which is generated by the electromagnetically induced transparency in the Rydberg medium. The setting supports diverse species of large-size polygonal soliton molecules, including rectangular and oblique rhombuses, checkerboard cells, and hexagons. The analysis identifies two distinct formation regimes. In the case of moderately nonlocality, the long-range interactions alone stabilize the soliton molecules in the static form. In contrast, in the strongly nonlocal regime, initially imposed rotation is required to generate a centrifugal force that counteracts the strong attraction, resulting in stably rotating soliton molecules. The rotation period can be controlled by adjusting the system parameters. Furthermore, appropriate initial velocities can induce inherent breathing dynamics in the solitons, leading to the formation of breather molecules. Tuning the initial velocity, one can control the evolution of soliton molecules and breather molecules and even realize their mutual conversion. Our study offers a new scheme for engineering soliton molecules and breather molecules, and suggests new possibilities for the design of data processing and transmission in optical systems. △ Less

Submitted 1 July, 2026; v1 submitted 23 March, 2026; originally announced March 2026.

Comments: 15 pages, 9 figures

FuXiWeather2: Learning accurate atmospheric state estimation for operational global weather forecasting

Authors: Xiaoze Xu, Xiuyu Sun, Songling Zhu, Xiaohui Zhong, Yuanqing Huang, Zijian Zhu, Jun Liu, Hao Li

Abstract: Numerical weather prediction has long been constrained by the computational bottlenecks inherent in data assimilation and numerical modeling. While machine learning has accelerated forecasting, existing models largely serve as "emulators of reanalysis products," thereby retaining their systematic biases and operational latencies. Here, we present FuXiWeather2, a unified end-to-end neural framework… ▽ More Numerical weather prediction has long been constrained by the computational bottlenecks inherent in data assimilation and numerical modeling. While machine learning has accelerated forecasting, existing models largely serve as "emulators of reanalysis products," thereby retaining their systematic biases and operational latencies. Here, we present FuXiWeather2, a unified end-to-end neural framework for assimilation and forecasting. We align training objectives directly with a combination of real-world observations and reanalysis data, enabling the framework to effectively rectify inherent errors within reanalysis products. To address the distribution shift between NWP-derived background inputs during training and self-generated backgrounds during deployment, we introduce a recursive unrolling training method to enhance the precision and stability of analysis generation. Furthermore, our model is trained on a hybrid dataset of raw and simulated observations to mitigate the impact of observational distribution inconsistency. FuXiWeather2 generates high-resolution ($0.25^{\circ}$) global analysis fields and 10-day forecasts within minutes. The analysis fields surpass the NCEP-GFS across most variables and demonstrate superior accuracy over both ERA5 and the ECMWF-HRES system in lower-tropospheric and surface variables. These high-quality analysis fields drive deterministic forecasts that exceed the skill of the HRES system in 91\% of evaluated metrics. Additionally, its outstanding performance in typhoon track prediction underscores its practical value for rapid response to extreme weather events. The FuXiWeather2 analysis dataset is available at https://doi.org/10.5281/zenodo.18872728. △ Less

Submitted 16 March, 2026; originally announced March 2026.

Non-volatile Multistate Magnetic Switching via Spin-orbit Torque and Intrinsic Anisotropy

Authors: Fei Ye, Chunzheng Wang, Xue Zhang, Sihai Jiao, Zhongjie Wang, Long Cheng, Zhifeng Zhu, Chunlei Gao, Xiaofang Zhai

Abstract: While current-induced bistate spin-orbit torque (SOT) switching has been well established, deterministic electrical control of multiple magnetic states remains a central challenge in spintronics. Here, we realize a conceptually new multistate SOT device in a SrIrO_3/SrRuO_3 bilayer, hosting four intrinsically stable yet electrically distinguishable magnetic states, including two in-plane canted (I… ▽ More While current-induced bistate spin-orbit torque (SOT) switching has been well established, deterministic electrical control of multiple magnetic states remains a central challenge in spintronics. Here, we realize a conceptually new multistate SOT device in a SrIrO_3/SrRuO_3 bilayer, hosting four intrinsically stable yet electrically distinguishable magnetic states, including two in-plane canted (IP_c^$\pm$) and two out-of-plane canted (OP_c^$\pm$) states. Pulsed current excitations fully map all twelve deterministic transitions among the four states, establishing a robust switching protocol defined by two characteristic current densities. In-situ scanning nitrogen-vacancy (NV) center magnetometry provides direct real-space evidence for the previously unobserved IP_c^$\pm$ states, and spin dynamics simulations uncover a two-step switching pathway, driven by the concerted action of spin torques and the effective anisotropy field within the fourfold anisotropy landscape. Our demonstration of the intrinsic multistate SOT device directly addresses the density bottleneck of conventional bistate SOT technology, establishing a powerful paradigm for compact, high-speed, and energy-efficient multistate spintronics. △ Less

Submitted 12 March, 2026; originally announced March 2026.

Fewest-Switches Surface Hopping with Combined Deep Learning Potential and Long Short-Term Memory Network Propagator for Simulating Realistic Photochemical Processes

Authors: Zhenxing Zhu, Diandong Tang, Lin Shen, Wei-Hai Fang

Abstract: Fewest-switches surface hopping (FSSH) is the most popular method for simulating photochemical processes of molecular systems. Recently, we have constructed long short-term memory (LSTM) networks as a propagator for electronic subsystems in FSSH dynamics simulations. The collective results on Tully's three models have been reproduced satisfactorily. In the present work, we develop an extended LSTM… ▽ More Fewest-switches surface hopping (FSSH) is the most popular method for simulating photochemical processes of molecular systems. Recently, we have constructed long short-term memory (LSTM) networks as a propagator for electronic subsystems in FSSH dynamics simulations. The collective results on Tully's three models have been reproduced satisfactorily. In the present work, we develop an extended LSTM-FSSH framework to simulate realistic photochemical reactions. The input features of LSTM as well as the training procedure are redesigned to represent high-dimensional nuclear degrees of freedom in an effective way. Equivariant neural networks are integrated with LSTM to build adiabatic potential energy surfaces in ground and excited states. Photoisomerizations of $\mathrm{CH_2NH}$ and azobenzene are simulated, showing that our new proposed LSTM-FSSH method can produce excited-state lifetimes and product yields accurately in comparison with conventional FSSH simulations as reference. Only 10 reference trajectories are required for training LSTM networks, and then a trajectory ensemble can be generated with very efficient LSTM-FSSH dynamics simulations to obtain collective results. △ Less

Submitted 22 May, 2026; v1 submitted 29 January, 2026; originally announced January 2026.

Comments: SI included

Burst Mode Ultrafast Laser Welding of Sapphire and Fe-36Ni Alloy with Non-optical Contact Condition

Authors: Yu Wang, Nan Li, Yuxuan Li, Yitong Chen, Qingwei Zhang, Jianing Zhao, Zhe Lin, Zihui Dong, Guochang Jiang, Zhengqiang Zhu, Shanglu Yang

Abstract: Ultrafast laser welding provides a promising approach for high precision integration of transparent and metallic materials. However, its practical application remains constrained by the precise regulation of the interfacial gap. This study investigates the interfacial response and bonding mechanism of sapphire and Fe-36Ni alloy joints under controlled non-optical contact conditions using burst mod… ▽ More Ultrafast laser welding provides a promising approach for high precision integration of transparent and metallic materials. However, its practical application remains constrained by the precise regulation of the interfacial gap. This study investigates the interfacial response and bonding mechanism of sapphire and Fe-36Ni alloy joints under controlled non-optical contact conditions using burst mode ultrafast laser irradiation. A polymer interlayer was introduced between naturally stacked samples to establish a variable interfacial gap, allowing systematic evaluation of gap-dependent morphology, melting behavior, and elemental transport. By redistributing the pulse energy into sequential sub-pulses, the burst mode reconstructs the temporal energy-deposition process, yielding enhanced plasma-material coupling and stable thermal accumulation. Compared with single pulse irradiation, burst mode sustains continuous bonding across gaps exceeding 10 um--far beyond the failure threshold of the single pulse mode--and forms a fusion zone 82% larger. Fracture surface and cross-sectional analyses of SEM and EDS results confirm that sequential sub-pulses promote extensive sapphire melting, droplet-driven gap bridging, and enhanced Al-Fe interdiffusion at the interface. These results provide a scientific basis for high-gap-tolerance ultrafast laser welding and scalable integration of transparent-metal hybrid components in advanced optoelectronic and precision engineering applications. △ Less

Submitted 21 January, 2026; originally announced January 2026.

Comments: 11 pages, 6 figures

MSC Class: 78A60

Space and space-time topologies in a type-II hyperbolic lattice

Authors: Jingming Chen, Zebin Zhu, Minqi Cheng, Linyun Yang, Yuxin Zhong, Zhen Gao

Abstract: Recent breakthroughs in hyperbolic lattices have expanded the study of topological phases of matter from Euclidean to non-Euclidean spaces. However, prior work has mostly focused on spatial topological states at the single outer edge of type-I hyperbolic lattices. The dynamic transfer of hyperbolic topological states across multiple edges, as well as the emergence of spatiotemporal topological phe… ▽ More Recent breakthroughs in hyperbolic lattices have expanded the study of topological phases of matter from Euclidean to non-Euclidean spaces. However, prior work has mostly focused on spatial topological states at the single outer edge of type-I hyperbolic lattices. The dynamic transfer of hyperbolic topological states across multiple edges, as well as the emergence of spatiotemporal topological phenomena, remains largely unexplored. Here, we establish both spatial and spatiotemporal topologies in a newly discovered type-II hyperbolic lattice possessing outer and inner edges. Using electric circuits, we experimentally realize a type-II hyperbolic Chern insulator and directly observe degenerate chiral edge states of opposite chirality at its outer and inner edges. Furthermore, by coupling these counter-propagating chiral edge states, we demonstrate an anti-time-parity phase transition, enabling dynamic transfer between them in arbitrary proportions. Finally, we propose a novel paradigm for constructing a (2+1)-dimensional hyperbolic space-time crystal, which hosts an intertwined topology of spatial Chern and temporal winding numbers, resulting in a unique space-time topological string state. Our work expands the frontier of hyperbolic topological physics, paving the way for the spatiotemporal dynamic manipulation of hyperbolic topological states. △ Less

Submitted 13 January, 2026; originally announced January 2026.

Upstream Laser-based Longitudinal Enhancement of Relativistic Photoelectrons

Authors: Hao Zhang, Randy Lemons, Jack Hirschman, Nicole Neveu, Nicolas Sudar, River Robles, Paris Franz, David Cesar, Zihan Zhu, Mathew Britton, Kurtis Borne, Zhen Zhang, Kirk A. Larsen, Benjamin Mencer, Justin Baker, Chad Pennington, Razib Obaid, Yuantao Ding, Ryan Coffee, Gabriel Just, Feng Zhou, Ji Qiang, James Cryan, Joseph Robinson, Agostino Marinelli , et al. (1 additional authors not shown)

Abstract: Controlling the longitudinal phase space of high-brightness relativistic electron beams is crucial for advancing a broad spectrum of charged-particle-based instrumentation and scientific frontiers. A generalized method for achieving this control involves manipulating the photoemission laser's temporal distribution at the picosecond level, a long-standing technical challenge. Recent developments in… ▽ More Controlling the longitudinal phase space of high-brightness relativistic electron beams is crucial for advancing a broad spectrum of charged-particle-based instrumentation and scientific frontiers. A generalized method for achieving this control involves manipulating the photoemission laser's temporal distribution at the picosecond level, a long-standing technical challenge. Recent developments in laser shaping have enabled the creation of high-power, picosecond-scale symmetrical and asymmetrical temporal profiles, capable of fine-tuning complex space-charge dynamics and external field effects in relativistic charged-particle beams. Here, we demonstrate that rather than deviations from theorized, idealized laser distributions, a controlled asymmetry can be harnessed to counteract accelerator-induced distortions. By implementing spatiotemporal shaping of the ultraviolet photocathode laser at the LCLS-II superconducting injector, we achieve deterministic control over the longitudinal phase space without downstream corrections. We find that this optical asymmetry induces a self-linearizing effect across both low (40 pC) and high (80 pC) charge regimes, effectively suppressing nonlinear compression and energy chirp. Consequently, this approach is expected to preserve a low emittance comparable to that of ideal flattop or regular Gaussian profiles, while delivering superior current uniformity and shot-to-shot stability. These results establish spatiotemporal laser shaping as a compact, generalizable tool for directly optimizing beam brightness at the source. △ Less

Submitted 6 January, 2026; originally announced January 2026.

Enabling Ultra-Fast Cardiovascular Imaging Across Heterogeneous Clinical Environments with A Generalist Foundation Model and Multimodal Database

Authors: Zi Wang, Mingkai Huang, Zhang Shi, Hongjie Hu, Lan Lan, Hui Zhang, Yan Li, Xi Hu, Qing Lu, Zongming Zhu, Qiong Yao, Yuxiang Dai, Fanwen Wang, Yinzhe Wu, Jun Lyu, Qianqian Gao, Guangming Xu, Zhenxuan Zhang, Haosen Zhang, Qing Li, Guangming Wang, Tianxing He, Lizhen Lan, Siyue Li, Le Xue , et al. (39 additional authors not shown)

Abstract: Multimodal cardiovascular magnetic resonance (CMR) imaging provides comprehensive and non-invasive insights into cardiovascular disease (CVD) diagnosis and underlying mechanisms. Despite decades of advancements, its widespread clinical adoption remains constrained by prolonged scan times, inconsistent image quality, and heterogeneity across medical environments. This underscores the urgent need fo… ▽ More Multimodal cardiovascular magnetic resonance (CMR) imaging provides comprehensive and non-invasive insights into cardiovascular disease (CVD) diagnosis and underlying mechanisms. Despite decades of advancements, its widespread clinical adoption remains constrained by prolonged scan times, inconsistent image quality, and heterogeneity across medical environments. This underscores the urgent need for a generalist reconstruction foundation model for ultra-fast CMR imaging, one formulated for physics-constrained inverse problems in the sensor (k-space) domain, capable of adapting across diverse imaging scenarios and serving as the essential substrate for all downstream analyses. To enable this goal, we curate MMCMR-427K, the largest and most comprehensive multimodal CMR k-space database to date, comprising 427,465 multi-coil k-space data paired with structured metadata across 13 international centers, 12 CMR modalities, 15 scanners spanning four field strengths, and 17 CVD categories in populations across three continents. Building on this unprecedented resource, we introduce CardioMM, a generalist reconstruction foundation model capable of dynamically adapting to heterogeneous fast CMR imaging scenarios. CardioMM unifies semantic contextual understanding with physics-informed data consistency to deliver robust reconstructions across varied scanners, protocols, and patient presentations. Comprehensive evaluations demonstrate that CardioMM achieves state-of-the-art performance across internal centers and exhibits strong zero-shot generalization to unseen external settings. Importantly, CardioMM supports acceleration up to 24x, providing the first evidence that such extreme acquisition speed can preserve key cardiac phenotypes, quantitative myocardial biomarkers, and diagnostic image quality without compromising clinical integrity. △ Less

Submitted 14 April, 2026; v1 submitted 25 December, 2025; originally announced December 2025.

Comments: Github: https://github.com/wangziblake/CardioMM_MMCMR-427K

All-optical control and multiplexed readout of multiple superconducting qubits

Authors: Xiaoxuan Pan, Chuanlong Ma, Jia-Qi Wang, Zheng-Xu Zhu, Linze Li, Jiajun Chen, Yuan-Hao Yang, Yilong Zhou, Jia-Hua Zou, Xin-Biao Xu, Weiting Wang, Baile Chen, Haifeng Yu, Chang-Ling Zou, Luyan Sun

Abstract: Superconducting quantum circuits operate at millikelvin temperatures, typically requiring independent microwave cables for each qubit for connecting room-temperature control and readout electronics. However, scaling to large-scale processors hosting hundreds of qubits faces a severe input/output (I/O) bottleneck, as the dense cable arrays impose prohibitive constraints on physical footprint, therm… ▽ More Superconducting quantum circuits operate at millikelvin temperatures, typically requiring independent microwave cables for each qubit for connecting room-temperature control and readout electronics. However, scaling to large-scale processors hosting hundreds of qubits faces a severe input/output (I/O) bottleneck, as the dense cable arrays impose prohibitive constraints on physical footprint, thermal load, wiring complexity, and cost. Here we demonstrate a complete optical I/O architecture for superconducting quantum circuits, in which all control and readout signals are transmitted exclusively via optical photons. Employing a broadband traveling-wave Brillouin microwave-to-optical transducer, we achieve simultaneous frequency-multiplexed optical readout of two qubits. Combined with fiber-integrated photodiode arrays for control signal delivery, this closed-loop optical I/O introduces no measurable degradation to qubit coherence times, with an optically driven single-qubit gate fidelity showing only a 0.19% reduction relative to standard microwave operation. These results establish optical interconnects as a viable path toward large-scale superconducting quantum processors, and open the possibility of networking multiple superconducting quantum computers housed in separate dilution refrigerators through a centralized room-temperature control infrastructure. △ Less

Submitted 24 December, 2025; originally announced December 2025.

Comments: 7 pages, 4 figures

Spatiotemporal topological phase transitions in photonic spacetime crystals

Authors: Zebin Zhu, Bolun Huang, Siqi Xu, Jingming Chen, Yan Meng, Zhenxiao Zhu, Xiang Xi, Zhen Gao

Abstract: Topological phase transitions, characterized by the closing and reopening of band gaps and a concomitant change in topological invariants, have played a central role in topological physics. However, such transitions have so far been restricted to spatial crystals, relying solely on energy band gaps and spatial interfaces. Here, we transcend this conventional framework and report, for the first tim… ▽ More Topological phase transitions, characterized by the closing and reopening of band gaps and a concomitant change in topological invariants, have played a central role in topological physics. However, such transitions have so far been restricted to spatial crystals, relying solely on energy band gaps and spatial interfaces. Here, we transcend this conventional framework and report, for the first time, spatiotemporal topological phase transition in photonic spacetime crystals - structures that are periodically modulated in both space and time. Using a dynamically modulated transmission line metamaterial, we theoretically propose and experimentally demonstrate complete spatiotemporal topological phase transitions characterized by the closing and reopening of both energy and momentum band gaps, alongside changes in spatiotemporal topological invariants and topological phases. Furthermore, in a genuine photonic spacetime crystal that possesses a complete energy-momentum band gap, we directly observe a space-time topological event that localizes in both space and time, exhibiting relativistic-causality-governed excitation and robustness against spatiotemporal disorders. Our findings reveal the interplay among space, time, and topology, establishing a unified framework that provides a comprehensive picture of the emerging topological space-time physics and opening new avenues for robust spatiotemporal topological wave manipulations. △ Less

Submitted 18 December, 2025; originally announced December 2025.

Comments: 15 pages, 4 figures

Multimode Jahn-Teller Effect in Negatively Charged Nitrogen-Vacancy Center in Diamond

Authors: Jianhua Zhang, Jun Liu, Z. Z. Zhu, K. M. Ho, V. V. Dobrovitski, C. Z. Wang

Abstract: We present a first-principles study of the multimode Jahn-Teller (JT) effect in the exctied $^{3}E$ state of the negatively charged nitrogen-vacancy (NV) center in diamond. Using density functional theory combined with an intrinsic distortion path (IDP) analysis, we resolve the full activation pathways of the JT distortion and quantitatively decompose the distortion into contributions from individ… ▽ More We present a first-principles study of the multimode Jahn-Teller (JT) effect in the exctied $^{3}E$ state of the negatively charged nitrogen-vacancy (NV) center in diamond. Using density functional theory combined with an intrinsic distortion path (IDP) analysis, we resolve the full activation pathways of the JT distortion and quantitatively decompose the distortion into contributions from individual vibrational modes. We find that multiple vibrational modes participate cooperatively in the JT dynamics, giving rise to a shallow adiabatic potential energy surface with low barriers, consistent with thermally activated pseudorotation. The dominant JT-active modes are found to closely correspond to vibrational features observed in two-dimensional electronic spectroscopy (2DES), in agreement with recent ab initio molecular dynamics simulations. Our results establish a microscopic, mode-resolved picture of vibronic coupling in the excited-state NV center and provide new insight into dephasing, relaxation, and optically driven dynamics relevant to solid-state quantum technologies. △ Less

Submitted 31 January, 2026; v1 submitted 16 December, 2025; originally announced December 2025.

CTransformer: Deep-transformer-based 3D cell membrane tracking with subcellular-resolved molecular quantification

Authors: Zelin Li, Guoye Guan, Xiu Xian, Dongying Xie, Yiming Ma, Sicheng You, Zhen Zhu, Darrick Lee, Zirui Zhang, Zhuohen Ran, Chenwei Wang, Jianfeng Cao, Chao Tang, Zhaoke Huang, Zhongying Zhao, Hong Yan

Abstract: Deep learning segmentation and fluorescence imaging techniques allow the cellular morphology of living embryos to be constructed spatiotemporally. These development processes involve numerous molecules distributed at the subcellular scale, such as cell adhesion (E-cadherin), which accumulate at cell-cell interfaces to regulate intercellular connection. However, quantifying molecular distributions… ▽ More Deep learning segmentation and fluorescence imaging techniques allow the cellular morphology of living embryos to be constructed spatiotemporally. These development processes involve numerous molecules distributed at the subcellular scale, such as cell adhesion (E-cadherin), which accumulate at cell-cell interfaces to regulate intercellular connection. However, quantifying molecular distributions within specific subcellular regions across the entire embryo, where cell movement and molecular redistribution occur rapidly, is challenging due to the need for simultaneous cell morphology reconstruction and lineage tracing due to photobleaching and phototoxicity. We report a transformer-based pipeline, CTransformer, that establishes a 4D cellular morphology map before the 550-cell (late) stage. CTransformer constructed 4D cellular morphology atlases, reaching 80% accuracy at the 550-cell stage. Through this advanced architecture, we use only one channel to reconstruct cell morphology and achieve cell tracing. With each cell's morphology as a reference, the distribution of specific molecules throughout the cell body and at cell interfaces can be quantitatively measured in another fluorescence channel. We apply this methodology to track E-cadherin during embryonic development of the worm Caenorhabditis elegans, from fertilization to gastrulation. Our results reveal that E-cadherin is tightly regulated across individual embryos, both within single cells and at cell-cell interfaces, displaying an anterior-posterior gradient and cell- and lineage-specific patterns. Furthermore, its spatiotemporal heterogeneity influences cell mechanics and embryonic morphogenesis, helping explain how C. elegans achieves stereotypical developmental patterns at cellular resolution. △ Less

Submitted 16 December, 2025; originally announced December 2025.

Comments: 55 pages, 5 figures, 15 supplementary figures

Extended dissipaton theory for higher-order bath couplings and application to non-Condon spectroscopy with anharmonicity

Authors: Zi-Fan Zhu, Yu Su, Yao Wang, Rui-Xue Xu, YiJing Yan

Abstract: In this work, we develop an extended dissipaton theory that generalizes the environmental couplings beyond the conventional linear and quadratic forms, enabling the treatment of arbitrary order of bath couplings. Applying this theoretical framework to the condensed-phase non-Condon spectroscopy, we demonstrate the interplay of anharmonicity, non-Condon and solvent effects on optical spectra. Preci… ▽ More In this work, we develop an extended dissipaton theory that generalizes the environmental couplings beyond the conventional linear and quadratic forms, enabling the treatment of arbitrary order of bath couplings. Applying this theoretical framework to the condensed-phase non-Condon spectroscopy, we demonstrate the interplay of anharmonicity, non-Condon and solvent effects on optical spectra. Precise simulations are carried out with high efficiency on linear absorption spectra involving the above mentioned correlated effects. We exhibit how an anharmonic potential modulates the vibronic feature, offering insights into the role of nonlinear environmental couplings in spectroscopic signatures and exemplifying the success of the extended dissipaton formalism as an exact and efficient method for higher-order bath couplings. △ Less

Submitted 14 December, 2025; originally announced December 2025.

Comments: Part of Special Issue dedicated to Professor Qing-shi Zhu on the occasion of his 80th birthday

Scalable Optical Links for Controlling Bosonic Quantum Processors

Authors: Chuanlong Ma, Jia-Qi Wang, Linze Li, Jiajun Chen, Xiaoxuan Pan, Zheng-Hui Tian, Zheng-Xu Zhu, Jia-Hua Zou, Dingran Gu, Luyu Wang, Qiushi Chen, Weiting Wang, Xin-Biao Xu, Chang-Ling Zou, Baile Chen, Luyan Sun

Abstract: Superconducting quantum computing has the potential to revolutionize computational capabilities. However, scaling up large quantum processors is limited by the cumbersome and heat-conductive electronic cables that connect room-temperature control electronics to quantum processors, leading to significant signal attenuation. Optical fibers provide a promising solution, but their use has been restric… ▽ More Superconducting quantum computing has the potential to revolutionize computational capabilities. However, scaling up large quantum processors is limited by the cumbersome and heat-conductive electronic cables that connect room-temperature control electronics to quantum processors, leading to significant signal attenuation. Optical fibers provide a promising solution, but their use has been restricted to controlling simple two-level quantum systems over short distances. Here, we demonstrate optical control of a bosonic quantum processor, achieving universal operations on the joint Hilbert space of a transmon qubit and a storage cavity. Using an array of cryogenic fiber-integrated uni-traveling-carrier photodiodes, we prepare Fock states containing up to ten photons. Additionally, remote control of bosonic modes over a transmission distance of 15 km has been achieved, with fidelities exceeding 95%. The combination of high-dimensional quantum control, multi-channel operation, and long-distance transmission addresses the key requirements for scaling superconducting quantum computers and enables architectures for distributed quantum data centers. △ Less

Submitted 11 December, 2025; originally announced December 2025.

Comments: 8 pages, 4 figures

FuXi-Nowcast: Environment-conditioned deep learning for severe convection nowcasting

Authors: Lei Chen, Zijian Zhu, Xiaoran Zhuang, Tianyuan Qi, Yuxuan Feng, Xiaohui Zhong, Hao Li

Abstract: Severe convection produces localized hazards that often require warnings before radar echoes fully reveal storm development. Convective initiation and the maintenance of intense convection remain challenging for radar-only nowcasting because pre-convective signals may be absent from recent radar observations and strong echoes often decay rapidly in forecasts. Here we present FuXi-Nowcast, an envir… ▽ More Severe convection produces localized hazards that often require warnings before radar echoes fully reveal storm development. Convective initiation and the maintenance of intense convection remain challenging for radar-only nowcasting because pre-convective signals may be absent from recent radar observations and strong echoes often decay rapidly in forecasts. Here we present FuXi-Nowcast, an environment-conditioned deep learning system that combines high-resolution observations with three-dimensional atmospheric forecasts to predict composite reflectivity, precipitation, wind gusts, and surface variables up to 12 h ahead. In April--July 2024 evaluations over East China, FuXi-Nowcast outperforms operational numerical, persistence and extrapolation baselines for reflectivity and precipitation. Case studies, diagnostics, and ablation experiments suggest that atmospheric moisture information and explicit preservation of strong convective signals contribute to forecasts of convective initiation and maintenance. These results show that environmental conditioning can mitigate important failure modes of radar-only nowcasting for high-impact convective weather. △ Less

Submitted 25 May, 2026; v1 submitted 2 December, 2025; originally announced December 2025.

Detailed study of non-equilibrium characteristics of quasi-neutral TNSA plasmas

Authors: Zhe Zhu, A. Bonasera, D. Batani, M. R. D. Rodrigues, K. Batani, J. A. Pérez-Hernández, M. Ehret, E. Filippov, H. Larreur, D. Molloy, G. G. Rapisarda, D. Lattuada, G. L. Guardo, C. Verona, Fe. Consoli, G. Petringa, A. McNamee, M. La Cognata, S. Palmerini, R. De Angelis, G. A. P. Cirrone, V. Istokskaia, R. Lera, L. Volpe, D. Giulietti , et al. (4 additional authors not shown)

Abstract: In an experiment performed in November 2022 at the petawatt (PW) laser facility at Vega III located in Salamanca-Spain, we have studied the successful production of several radioisotopes using protons accelerated by the Target Normal Sheath Acceleration (TNSA) mechanism (Rodrigues et al. [1]). The experimental proton energy distribution recorded on a shot-to-shot basis and confirmed in a follow up… ▽ More In an experiment performed in November 2022 at the petawatt (PW) laser facility at Vega III located in Salamanca-Spain, we have studied the successful production of several radioisotopes using protons accelerated by the Target Normal Sheath Acceleration (TNSA) mechanism (Rodrigues et al. [1]). The experimental proton energy distribution recorded on a shot-to-shot basis and confirmed in a follow up experiment (K. Batani et al. [2]), allowed us to derive the number of nuclear reactions taking place in different targets on a single shot. From this analysis, using the ratio of the yields 11C/7Be, we obtained an effective "single shot" temperature of the TNSA plasma. We used this value to evaluate the yield of alpha particles from the reaction p + 11B -> 3 alpha which may reach (1.6 +/- 0.5) x 10^9 alpha particles in 2pi. From the fluctuations of the protons and the fusion yields, we derived a "TNSA-Equation of State" (EoS), The deviation of such "EoS" from the classical ideal gas limit is well reproduced by the soliton solution of the Korteweg-de Vries (KdV) equation for each shot. △ Less

Submitted 7 May, 2026; v1 submitted 5 December, 2025; originally announced December 2025.

Comments: 21 pages, 11 figures

Subgrid Mean-field Dynamo Model with Dynamical Quenching in General Relativistic Magnetohydrodynamic Simulations

Authors: Hongzhe Zhou, Yosuke Mizuno, Zhenyu Zhu

Abstract: Large-scale magnetic fields are relevant for a number of dynamical processes in accretion disks, including driving turbulence, reconnection events, and launching outflows. Numerical simulations have indicated that the initial strengths and configurations of the large-scale magnetic fields have a direct imprint on the outcome of an accretion disk evolution. To facilitate future self-consistent simu… ▽ More Large-scale magnetic fields are relevant for a number of dynamical processes in accretion disks, including driving turbulence, reconnection events, and launching outflows. Numerical simulations have indicated that the initial strengths and configurations of the large-scale magnetic fields have a direct imprint on the outcome of an accretion disk evolution. To facilitate future self-consistent simulations that include intrinsic dynamo processes, we derive and implement a subgrid model of a helical large-scale dynamo with dynamical quenching in general-relativistic resistive magnetohydrodynamical simulations of geometrically thin accretion disks. By incorporating previous numerical and analytical results of helical dynamos, our model features only one input parameter, the viscosity parameter $α_\text{SS}$. We demonstrate that our model can reproduce butterfly diagrams seen in previous local and global simulations. With rather aggressive parameter choice of $α_\text{SS}=0.02$ and black hole spin $a_\text{BH}=0.9375$, our thin-disk model launches weak collimated polar outflows with Lorentz factor $\simeq 1.2$, but no polar outflow is present with less vigorous turbulence or less positive $a_\text{BH}$. With negative $a_\text{BH}$, we find the field configurations to appear more similar to Newtonian cases, whereas for positive $a_\text{BH}$, the poloidal field loops become distorted and the cycle period becomes sporadic or even disappears. Moreover, we demonstrate how $α_\text{SS}$ can avoid to be prescribed and instead be determined by the local plasma beta. Such a fully dynamical subgrid dynamo allows for self-consistent amplification of the large-scale magnetic fields. △ Less

Submitted 2 December, 2025; originally announced December 2025.

Comments: 16 pages, 13 figures; submitted

Acoustically control of integrated optical microrings: from photonic molecule to Mobius strip

Authors: Zheng-Xu Zhu, Yuan-Hao Yang, Xin-Biao Xu, Jia-Qi Wang, Yu Zeng, Jia-Hua Zou, Juanjuan Lu, Weiting Wang, Ming Li, Yan-Lei Zhang, Guang-Can Guo, Luyan Sun, Chang-Ling Zou

Abstract: Microring resonators (MRRs) are fundamental building blocks of photonic integrated circuits, yet their dynamic reconfiguration has been limited to tuning refractive index or absorption. Here, we demonstrate acoustic control over optical path topology on a lithium niobate on sapphire platform. By launching gigahertz acoustic waves into a hybrid phononic-photonic waveguide, a dynamic Bragg mirror (D… ▽ More Microring resonators (MRRs) are fundamental building blocks of photonic integrated circuits, yet their dynamic reconfiguration has been limited to tuning refractive index or absorption. Here, we demonstrate acoustic control over optical path topology on a lithium niobate on sapphire platform. By launching gigahertz acoustic waves into a hybrid phononic-photonic waveguide, a dynamic Bragg mirror (DBM) is created within the optical path, coupling forward and backward propagating light. Employing a pair of coupled MRRs, we achieve strong coupling between supermodes of the photonic molecule with only milliwatt-level drive power, yielding a cooperativity of 2.46 per milliwatt. At higher power, DBM reflectivity up to 24% is achieved, revealing breakdowns of both the photonic molecule picture and perturbative coupled mode theory, indicating the transformation toward Mobius strip topology. Our work establishes a new dimension for controlling photonic devices, opening pathways toward fully reconfigurable photonic circuits through acoustic drive. △ Less

Submitted 27 November, 2025; originally announced November 2025.

Comments: 8 pages, 4 figures

A universal framework for nonlinear frequency combs under electro-optic modulation

Authors: Yanyun Xue, Xianpeng Lv, Guangxing Wu, Tianqi Lei, Chenyang Cao, Yiming Lei, Min Wang, Zhendong Zhu, Yan Li, Qihuang Gong, Di Zhu, Yaowen Hu

Abstract: Nonlinear frequency combs, including electro-optic and Kerr combs, have become central platforms for chip-scale frequency synthesis. Recent breakthroughs in strong-coupling electro-optic modulation further expanded their accessible nonlinear dynamics, unlocking new phenomena and functionalities, but the underlying foundation remains largely unexplored. Here we establish a universal theoretical and… ▽ More Nonlinear frequency combs, including electro-optic and Kerr combs, have become central platforms for chip-scale frequency synthesis. Recent breakthroughs in strong-coupling electro-optic modulation further expanded their accessible nonlinear dynamics, unlocking new phenomena and functionalities, but the underlying foundation remains largely unexplored. Here we establish a universal theoretical and experimental framework for nonlinear combs under arbitrary electro-optic modulation by introducing a general evolution equation (GEE) that transcends the mean-field Lugiato-Lefever equation. The GEE reduces to a discrete-time Integration Hamiltonian that provides a frequency-domain formalism unifying strong-coupling electro-optic modulation with photonic synthetic dimensions. Together with a band-wave correspondence linking modulation waveforms to synthetic band structures, the formalism enables programmable spectral control. We further show compatibility between Kerr nonlinearity and strong-coupling electro-optic modulation, highlighting their cooperative dynamics. Our work provides a foundational model for strong-coupling electro-optics in nonlinear combs, opening a route toward chip-integrated, microwave-programmable comb sources for metrology, spectroscopy, and emerging photonic technologies. △ Less

Submitted 23 July, 2026; v1 submitted 25 November, 2025; originally announced November 2025.

Comments: 21 pages, 5 figures

Vehicle-Mounted Mid-Infrared Dual-Comb Spectroscopy for On-Road Trace Gas Detection

Authors: Xutian Jing, Kaiwen Wei, Chenglin Gu, Xiong Qin, Junwei Li, Xingyin Yang, Zhaoting Huang, Jianping Zhang, Chenhao Sun, Chenyu Liu, Zejiang Deng, Zhiwei Zhu, Daping Luo, Wenxue Li, Heping Zeng

Abstract: Advances in mid-infrared (MIR) dual-comb spectroscopy (DCS) have significantly enhanced molecular detection in recent years. The capability of DCS to precisely identify and quantify atmospheric trace gases makes it attractive for field applications across the environmental, agricultural, energy, and industrial sectors. In particular, there is a growing demand for mobile and continuous gas monitori… ▽ More Advances in mid-infrared (MIR) dual-comb spectroscopy (DCS) have significantly enhanced molecular detection in recent years. The capability of DCS to precisely identify and quantify atmospheric trace gases makes it attractive for field applications across the environmental, agricultural, energy, and industrial sectors. In particular, there is a growing demand for mobile and continuous gas monitoring in outdoor environments where emission sources and sinks are often episodic and spatially heterogeneous. However, the practical field-deployment of DCS on mobile platforms under realistic field conditions has remained limited. This study demonstrates for the first time a vehicle-mounted MIR DCS system that enables continuous mobile atmospheric sampling across multiple outdoor sites and road environments. The system exhibited a stable signal-to-noise performance during on-road operation, including expressway driving at speeds up to 100 km/h. Furthermore, natural-gas leakage sources were successfully located and a two-dimensional methane concentration field was reconstructed around a controlled release source. In the future, the system can be integrated into more mobile platforms, such as unmanned aerial vehicles, enabling flexible trace gas detection over urban-scale regions. △ Less

Submitted 10 March, 2026; v1 submitted 25 November, 2025; originally announced November 2025.

Comments: 12 pages, 8 figures

Initial performance results of the JUNO detector

Authors: Angel Abusleme, Thomas Adam, Kai Adamowicz, David Adey, Shakeel Ahmad, Rizwan Ahmed, Timo Ahola, Sebastiano Aiello, Fengpeng An, Guangpeng An, Costas Andreopoulos, Giuseppe Andronico, João Pedro Athayde Marcondes de André, Nikolay Anfimov, Vito Antonelli, Tatiana Antoshkina, Burin Asavapibhop, Didier Auguste, Margherita Buizza Avanzini, Andrej Babic, Jingzhi Bai, Weidong Bai, Nikita Balashov, Roberto Barbera, Andrea Barresi , et al. (1114 additional authors not shown)

Abstract: The Jiangmen Underground Neutrino Observatory (JUNO) started physics data taking on 26 August 2025. JUNO consists of a 20-kton liquid scintillator central detector, surrounded by a 35 kton water pool serving as a Cherenkov veto, and almost 1000 m$^2$ of plastic scintillator veto on top. The detector is located in a shallow underground laboratory with an overburden of 1800 m.w.e. This paper present… ▽ More The Jiangmen Underground Neutrino Observatory (JUNO) started physics data taking on 26 August 2025. JUNO consists of a 20-kton liquid scintillator central detector, surrounded by a 35 kton water pool serving as a Cherenkov veto, and almost 1000 m$^2$ of plastic scintillator veto on top. The detector is located in a shallow underground laboratory with an overburden of 1800 m.w.e. This paper presents the performance results of the detector, extensively studied during the commissioning of the water phase, the subsequent liquid scintillator filling phase, and the first physics runs. The liquid scintillator achieved an attenuation length of 20.6 m at 430 nm, while the high coverage PMT system and scintillator together yielded about 1785 photoelectrons per MeV of energy deposit at the detector centre, measured using the 2.223 MeV $γ$ from neutron captures on hydrogen with an Am-C calibration source. The reconstructed energy resolution is 3.4% for two 0.511 MeV $γ$ at the detector centre and 2.9% for the 0.93 MeV quenched Po-214 alpha decays from natural radioactive sources. The energy nonlinearity is calibrated to better than 1%. Intrinsic contaminations of U-238 and Th-232 in the liquid scintillator are below 10$^{-16}$ g/g, assuming secular equilibrium. The water Cherenkov detector achieves a muon detection efficiency better than 99.9% for muons traversing the liquid scintillator volume. During the initial science runs, the data acquisition duty cycle exceeded 97.8%, demonstrating the excellent stability and readiness of JUNO for high-precision neutrino physics. △ Less

Submitted 18 November, 2025; originally announced November 2025.

Comments: 38 pages, 23 figures

Compact and high-resolution spectrometer via Brillouin integrated circuits

Authors: Jia-Qi Wang, Yuan-Hao Yang, Zheng-Xu Zhu, Juan-Juan Lu, Ming Li, Xiaoxuan Pan, Chuanlong Ma, Lintao Xiao, Bo Zhang, Weiting Wang, Chun-Hua Dong, Xin-Biao Xu, Guang-Can Guo, Luyan Sun, Chang-Ling Zou

Abstract: Optical spectrometers are indispensable tools across various fields, from chemical and biological sensing to astronomical observations and quantum technologies. However, the integration of spectrometers onto photonic chips has been hindered by the low spectral resolution or large device footprint with complex multiple channel operations. Here, we introduce a novel chip-integrated spectrometer by l… ▽ More Optical spectrometers are indispensable tools across various fields, from chemical and biological sensing to astronomical observations and quantum technologies. However, the integration of spectrometers onto photonic chips has been hindered by the low spectral resolution or large device footprint with complex multiple channel operations. Here, we introduce a novel chip-integrated spectrometer by leveraging the acoustically-stimulated Brillouin scattering in a hybrid photonic-phononic chip. The Brillouin interaction provides a dynamic reflection grating with a high reflectivity up to 50% and a fast switching time on the microsecond scale, achieving an unprecedented spectral resolution of 0.56 nm over a 110 nm bandwidth using just a single 1 mm-long straight waveguide. This remarkable performance approaches the fundamental limit of resolution for a given device size, validating the potential of the hybrid photonic-phononic device for efficient and dynamically-reconfigurable spectral analysis, and thus opens up new avenues for advanced optical signal processing and sensing applications. △ Less

Submitted 6 November, 2025; originally announced November 2025.

Large-scale programmable phononic integrated circuits

Authors: Xin-Biao Xu, Yu Zeng, Jia-Qi Wang, Zheng-Hui Tian, Ji-Zhe Zhang, Yuan-Hao Yang, Zheng-Xu Zhu, Jia-Hua Zou, Liantao Xiao, Weiting Wang, Bao-Zhen Wang, Guang-Can Guo, Luyan Sun, Chang-Ling Zou

Abstract: Electronic and photonic chips revolutionized information technology through massive integration of functional elements, yet phonons as fundamental information carriers in solids remain underestimated. Here, we demonstrate large-scale programmable phononic integrated circuits (PnICs) for complex signal processing. We developed a comprehensive library of gigahertz-frequency phononic building blocks… ▽ More Electronic and photonic chips revolutionized information technology through massive integration of functional elements, yet phonons as fundamental information carriers in solids remain underestimated. Here, we demonstrate large-scale programmable phononic integrated circuits (PnICs) for complex signal processing. We developed a comprehensive library of gigahertz-frequency phononic building blocks that control acoustic wave propagation, polarization, and dispersion. Combining these elements, we demonstrate an ultra-compact 1$\times$128 on-chip acoustic power splitter with unprecedented integration density of 3,000/cm$^2$, a 21-port acoustic frequency demultiplexer with 3.8~MHz resolution, and a four-channel reconfigurable frequency synthesizer. This work establishes scalable phononic integration as the third pillar of information processing alongside electronics and photonics, enabling hybrid chips that combine all three domains for advanced signal processing and quantum information applications. △ Less

Submitted 30 October, 2025; originally announced October 2025.

Comments: 8 pages, 5 figures

Analysis of near wall flame and wall heat flux modeling in turbulent premixed combustion

Authors: Kunlin Li, Chenlin Guo, Zhaofan Zhu, Haiou Wang, Lipo Wang

Abstract: Reactive flows in confined spaces involve complex flame-wall interaction (FWI). This work aims to gain more insights into the physics of the premixed near-wall flame and the wall heat flux as an important engineering relevant quantity. Two different flame configurations have been studied, including the normal flushing flame and inclined sweeping flame. By introducing the skin friction vector defin… ▽ More Reactive flows in confined spaces involve complex flame-wall interaction (FWI). This work aims to gain more insights into the physics of the premixed near-wall flame and the wall heat flux as an important engineering relevant quantity. Two different flame configurations have been studied, including the normal flushing flame and inclined sweeping flame. By introducing the skin friction vector defined second-order tensor, direct numerical simulation (DNS) results of these two configurations show consistently that larger flame curvatures are associated with small vorticity magnitude under the influence of the vortex pair structure. Correlation of both the flame normal and tangential strain rates with the flame curvature has also been quantified. Alignment of the progress variable gradient with the most compressive eigenvector on the wall is similar to the boundary free behavior. To characterize the flame ordered structure, especially in the near-wall region, a species alignment index is proposed. The big difference in this index for flames in different regions suggests distinct flame structures. Building upon these fundamental insights, a predictive model for wall heat flux is proposed. For the purpose of applicability, realistic turbulent combustion situations need to be taken into account, for instance, flames with finite thickness, complex chemical kinetics, non-negligible near-wall reactions, and variable flame orientation relative to the wall. The model is first tested in an one-dimensional laminar flame and then validated against DNS datasets, justifying the model performance with satisfying agreement. △ Less

Submitted 30 October, 2025; originally announced October 2025.

Comments: submitted to Journal of Fluid Mechanics

Journal ref: Journal of Fluid Mechanics , Volume 1037 , 25 June 2026 , A40

The Phase-Coupled Caldeira-Leggett Model: Non-Markovian Open Quantum Dynamics beyond Linear Dissipation

Authors: Ao-Xiang Chang, Yu Su, Zi-Fan Zhu, Yao Wang, Rui-Xue Xu, YiJing Yan

Abstract: We introduce the \textit{Phase-Coupled Caldeira-Leggett} (PCL) model of quantum dissipation and develop an exact framework for its dynamics. Unlike the conventional Caldeira-Leggett model with linear system-bath coupling $H_{\mathrm{SB}}\propto\hat F$, the PCL model features an exponential interaction $H_{\mathrm{SB}}\propto e^{iλ\hat F}$, where $\hat F$ denotes the collective bath coordinate. Thi… ▽ More We introduce the \textit{Phase-Coupled Caldeira-Leggett} (PCL) model of quantum dissipation and develop an exact framework for its dynamics. Unlike the conventional Caldeira-Leggett model with linear system-bath coupling $H_{\mathrm{SB}}\propto\hat F$, the PCL model features an exponential interaction $H_{\mathrm{SB}}\propto e^{iλ\hat F}$, where $\hat F$ denotes the collective bath coordinate. This model unifies concepts from quantum Brownian motion and polaron physics, providing a general platform to study phase-mediated dissipation and decoherence beyond the linear-response regime. Despite its nonlinear system-bath coupling, the Gaussian nature of the environment allows a nonperturbative and non-Markovian treatment of PCL model within the algebra of dissipative quasiparticles. We obtain an exact closed-form equation of motion for the reduced density operator, and numerical simulations reveal distinctive dynamical behaviors that deviate markedly from those predicted by the conventional Caldeira-Leggett model. △ Less

Submitted 28 October, 2025; originally announced October 2025.

Comments: 3 pages, 4 figures

Anisotropic Hot Carrier Relaxation and Coherent Phonon Dynamics in Type-II Weyl Semimetal TaIrTe4

Authors: Zheng Zhu, Jingwen Wang, Hao Yu, Jialin Lu, Tianshu Lai, Peng Yu, Tianran Jiang, Ke Chen

Abstract: The unique energy band and crystal structure of the layered type-II Weyl semimetal TaIrTe4 hold great promise for high-performance broadband anisotropic optoelectronic devices. Therefore, gaining an in-depth understanding of the interactions between internal microscopic particles is of vital importance. Here, we employ a two-color pump-probe system to reveal the anisotropic electron-phonon couplin… ▽ More The unique energy band and crystal structure of the layered type-II Weyl semimetal TaIrTe4 hold great promise for high-performance broadband anisotropic optoelectronic devices. Therefore, gaining an in-depth understanding of the interactions between internal microscopic particles is of vital importance. Here, we employ a two-color pump-probe system to reveal the anisotropic electron-phonon coupling (EPC) and coherent phonon dynamics in bulk TaIrTe4. The carrier relaxation exhibits a four-exponential decay process, with strong dependence on polarization of probe pulse, indicating that EPC strength is closely related to the crystal axes (a/b-axes). In addition, we observe three coherent phonon modes in bulk TaIrTe4: 38.5 GHz, 0.44 THz and 1.29 THz. Their oscillation amplitudes and dephasing times also show anisotropic responses to the probe polarization. We also investigate the in-plane cross-directional thermal conductivity coefficient of TaIrTe4 by beam-offset frequency-domain thermal reflection (FDTR). The thermal conductivity coefficient along the a-axis and b-axis directions are ka=14.4 W/mK and kb=3.8 W/mK, respectively. This represents a significant in-plane anisotropy. Our work not only reveals the key role of anisotropic EPC in controlling the thermal and optical properties of TaIrTe4, but also provides insights into designing polarization-sensitive optoelectronic devices based on topological semimetals. △ Less

Submitted 28 October, 2025; originally announced October 2025.

Comments: 22 pages, 5 figures

Suspension-Free Integrated Cavity Brillouin Optomechanics on a Chip

Authors: Yuan-Hao Yang, Jia-Qi Wang, Zheng-Xu Zhu, Xin-Biao Xu, Ming Li, Juanjuan Lu, Guang-Can Guo, Luyan Sun, Chang-Ling Zou

Abstract: Cavity optomechanical systems enable coherent photon-phonon interactions essential for quantum technologies, yet high-performance devices have been limited to suspended structures. Here, we overcome this limitation by demonstrating cavity Brillouin optomechanics in a suspension-free racetrack microring resonator on a lithium-niobate-on-sapphire chip, a platform that merits high stability and scala… ▽ More Cavity optomechanical systems enable coherent photon-phonon interactions essential for quantum technologies, yet high-performance devices have been limited to suspended structures. Here, we overcome this limitation by demonstrating cavity Brillouin optomechanics in a suspension-free racetrack microring resonator on a lithium-niobate-on-sapphire chip, a platform that merits high stability and scalability. We demonstrate coherent coupling between telecom-band optical modes and a 9.6-GHz phonon mode, achieving a maximum cooperativity of $0.41$ and a phonon quality-factor-frequency product of $10^{13}\,\mathrm{Hz}$. The momentum-matching condition inherent to traveling-wave Brillouin interactions establishes a one-to-one mapping between optical wavelength and phonon frequency, enabling multi-channel parallel operations across nearly $300\,\mathrm{MHz}$ in phonon frequency and $40\,\mathrm{nm}$ in optical wavelength. Our suspension-free architecture provides a coherent photon-phonon interface compatible with wafer-scale integration, opening pathways toward hybrid quantum circuits that unite photonic, phononic, and superconducting components on a single chip. △ Less

Submitted 23 October, 2025; originally announced October 2025.

Comments: 6 pages, 4 figures

Identifying the Catalytic Descriptor of Single-Atom Catalysts in Nitrate Reduction Reaction: An Interpretable Machine-Learning Method

Authors: Zhen Zhu, Shan Gao, Jing Zhang, Xuxin Kang, Shunfang Li, Xiangmei Duan

Abstract: Elucidating the catalytic descriptor that accurately characterizes the structure-activity relationships of typical catalysts for various important heterogeneous catalytic reactions is pivotal for designing high-efficient catalytic systems. Here, an interpretable machine learning technique was employed to identify the key determinants governing the nitrate reduction reaction ($\rm NO_3RR$) performa… ▽ More Elucidating the catalytic descriptor that accurately characterizes the structure-activity relationships of typical catalysts for various important heterogeneous catalytic reactions is pivotal for designing high-efficient catalytic systems. Here, an interpretable machine learning technique was employed to identify the key determinants governing the nitrate reduction reaction ($\rm NO_3RR$) performance across 286 single-atom catalysts (SACs) with the active sites anchored on double-vacancy $\rm BC_3$ monolayers. Through Shapley Additive Explanations (SHAP) analysis with reliable predictive accuracy, we quantitatively demonstrated that, favorable $\rm NO_3RR$ activity stems from a delicate balance among three critical factors: low $\rm N_V$, moderate $\rm D_N$, and specific doping patterns. Building upon these insights, we established a descriptor ($ψ$) that integrates the intrinsic catalytic properties and the intermediate O-N-H angle ($θ$), effectively capturing the underlying structure-activity relationship. Guided by this, we further identified 16 promising catalysts with predicted low limiting potential ($U_{\rm L}$). Importantly, these catalysts are composed of cost-effective non-precious metal elements and are predicted to surpass most reported catalysts, with the best-performing Ti-V-1N1 is predicted to have an ultra-low $U_{\rm L}$ of $-0.10$ V. △ Less

Submitted 22 October, 2025; originally announced October 2025.

Comments: 10 pages, 8 figures, 74 references

Proposal for Forward Brillouin Inter-Modal Scattering in Non-suspended Lithium Niobate Waveguides at Visible Wavelengths

Authors: Jia-Lin Chen, Yuan-Hao Yang, Zheng-Xu Zhu, Jia-Qi Wang, Xin-Biao Xu, Ming Li, Zheng-Fu Han, Guang-Can Guo, Wei Chen, Chang-Ling Zou

Abstract: Thin-film lithium niobate on sapphire provides an excellent platform for simultaneously confining acoustic and optical modes without suspended structures, enabling efficient acousto-optic modulation through strong piezoelectric coupling. Here, we identify the challenges in realizing the forward Brillouin interaction at visible wavelengths, and overcome the limitation by introducing a quasi-phase-m… ▽ More Thin-film lithium niobate on sapphire provides an excellent platform for simultaneously confining acoustic and optical modes without suspended structures, enabling efficient acousto-optic modulation through strong piezoelectric coupling. Here, we identify the challenges in realizing the forward Brillouin interaction at visible wavelengths, and overcome the limitation by introducing a quasi-phase-matching scheme through periodic waveguide width modulation. We predict a complete inter-modal optical conversion over 1.1 mm using only 1 mW acoustic power. Our study paves the way for high-performance visible-wavelength acousto-optic devices on integrated platforms. △ Less

Submitted 9 October, 2025; originally announced October 2025.

Comments: 5 pages, 4 figures

Design, waterproofing, and mass production of the 3-inch PMT frontend system of JUNO

Authors: Jilei Xu, Miao He, Cédric Cerna, Yongbo Huang, Thomas Adam, Shakeel Ahmad, Rizwan Ahmed, Fengpeng An, Costas Andreopoulos, Giuseppe Andronico, João Pedro Athayde Marcondes de André, Nikolay Anfimov, Vito Antonelli, Tatiana Antoshkina, Didier Auguste, Weidong Bai, Nikita Balashov, Andrea Barresi, Davide Basilico, Eric Baussan, Marco Beretta, Antonio Bergnoli, Nikita Bessonov, Daniel Bick, Lukas Bieger , et al. (609 additional authors not shown)

Abstract: Over 25,600 3-inch photomultiplier tubes (PMTs) have been instrumented for the central detector of the Jiangmen Underground Neutrino Observatory. Each PMT is equipped with a high-voltage divider and a frontend cable with waterproof sealing. Groups of sixteen PMTs are connected to the underwater frontend readout electronics via specialized multi-channel waterproof connectors. This paper outlines th… ▽ More Over 25,600 3-inch photomultiplier tubes (PMTs) have been instrumented for the central detector of the Jiangmen Underground Neutrino Observatory. Each PMT is equipped with a high-voltage divider and a frontend cable with waterproof sealing. Groups of sixteen PMTs are connected to the underwater frontend readout electronics via specialized multi-channel waterproof connectors. This paper outlines the design and mass production processes for the high-voltage divider, the cable and connector, as well as the waterproof potting of the PMT bases. The results of the acceptance tests of all the integrated PMTs are also presented. △ Less

Submitted 22 January, 2026; v1 submitted 7 October, 2025; originally announced October 2025.

A Particle-in-Cell Simulation Framework for Thomson Scattering Analysis in Inertial Confinement Fusion

Authors: Ziang Zhu, Yifan Liu, Jun Li, Han Wen, Shihui Cao, Yin Shi, Qing Jia, Chaoxin Chen, Yaoyuan Liu, Hang Zhao, Tao Gong, Zhichao Li, Dong Yang, Jian Zheng

Abstract: In inertial confinement fusion (ICF), Thomson scattering (TS) is a widely used diagnostic technique for probing plasma conditions. We present a first-principles numerical approach to obtaining scattered light signals of ion acoustic features with high resolution in angle and frequency space using particle-in-cell simulations under typical ICF conditions. Our method demonstrates good agreement with… ▽ More In inertial confinement fusion (ICF), Thomson scattering (TS) is a widely used diagnostic technique for probing plasma conditions. We present a first-principles numerical approach to obtaining scattered light signals of ion acoustic features with high resolution in angle and frequency space using particle-in-cell simulations under typical ICF conditions. Our method demonstrates good agreement with existing theories for thermal collective TS. In the super-thermal collective regime, the results align with theory when the driven plasma modes are well-matched in wave vectors to the probe and collecting beams. Moreover, we also find that TS signals can remain significant even under imperfect wave-vector matching-a result that contradicts the conventional expectation that the TS spectrum strictly follows the plasma density spectrum. We attribute this discrepancy to a beating wave mechanism arising from the interaction between the probe beam and driven plasma density modulations. Our work thus provides a practical framework for interpreting TS signals from driven ion modes, a common yet complex feature in ICF plasmas. △ Less

Submitted 22 February, 2026; v1 submitted 5 October, 2025; originally announced October 2025.