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Terahertz-field activation of polar skyrons
Authors:
Huaiyu Wang,
Vladimir Stoica,
Cheng Dai,
Marek Paściak,
Sujit Das,
Tiannan Yang,
Mauro A. P. Gonçalves,
Jiri Kulda,
Margaret R. McCarter,
Anudeep Mangu,
Yue Cao,
Hari Padma,
Utkarsh Saha,
Diling Zhu,
Takahiro Sato,
Sanghoon Song,
Mathias Hoffmann,
Patrick Kramer,
Silke Nelson,
Yanwen Sun,
Quynh Nguyen,
Zhan Zhang,
Ramamoorthy Ramesh,
Lane Martin,
Aaron M. Lindenberg
, et al. (5 additional authors not shown)
Abstract:
Unraveling collective modes arising from coupled degrees of freedom is crucial for understanding complex interactions in solids and developing new functionalities. Unique collective behaviors emerge when two degrees of freedom, ordered on distinct length scales, interact. Polar skyrmions, three-dimensional electric polarization textures in ferroelectric superlattices, disrupt the lattice continuit…
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Unraveling collective modes arising from coupled degrees of freedom is crucial for understanding complex interactions in solids and developing new functionalities. Unique collective behaviors emerge when two degrees of freedom, ordered on distinct length scales, interact. Polar skyrmions, three-dimensional electric polarization textures in ferroelectric superlattices, disrupt the lattice continuity at the nanometer scale with nontrivial topology, leading to previously unexplored collective modes. Here, using terahertz-field excitation and femtosecond x-ray diffraction, we discovered subterahertz collective modes, dubbed 'skyrons', which appear as swirling patterns of atomic displacements functioning as atomic-scale gearsets. Momentum-resolved time-domain measurements of diffuse scattering revealed an avoided crossing in the dispersion relation of skyrons. We further demonstrated that the amplitude and dispersion of skyrons can be controlled by sample temperature and electric-field bias. Atomistic simulations and dynamical phase-field modeling provided microscopic insights into the three-dimensional crystallographic and polarization dynamics. The discovery of skyrons and their coupling with terahertz fields opens avenues for ultrafast control of topological polar structures.
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Submitted 1 September, 2025; v1 submitted 15 May, 2025;
originally announced May 2025.
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Nonresonant Raman control of ferroelectric polarization
Authors:
Jiaojian Shi,
Christian Heide,
Haowei Xu,
Yuejun Shen,
Meredith Henstridge,
Isabel Sedwick,
Anudeep Mangu,
Xinyue Peng,
Shangjie Zhang,
Mariano Trigo,
Tony F. Heinz,
Ju Li,
Keith A. Nelson,
Edoardo Baldini,
Jian Zhou,
Shambhu Ghimire,
David A. Reis,
Aaron M. Lindenberg
Abstract:
Important advances have recently been made in the search for materials with complex multi-phase landscapes that host photoinduced metastable collective states with exotic functionalities. In almost all cases so far, the desired phases are accessed by exploiting light-matter interactions via the imaginary part of the dielectric function through above-bandgap or resonant mode excitation. Nonresonant…
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Important advances have recently been made in the search for materials with complex multi-phase landscapes that host photoinduced metastable collective states with exotic functionalities. In almost all cases so far, the desired phases are accessed by exploiting light-matter interactions via the imaginary part of the dielectric function through above-bandgap or resonant mode excitation. Nonresonant Raman excitation of coherent modes has been experimentally observed and proposed for dynamic material control, but the resulting atomic excursion has been limited to perturbative levels. Here, this challenge is overcome by employing nonresonant ultrashort pulses with low photon energies well below the bandgap. Using mid-infrared pulses, ferroelectric reversal is induced in lithium niobate, and the large-amplitude mode displacements are characterized through femtosecond stimulated Raman scattering and second harmonic generation. This approach, validated by first-principle calculations, defines a novel method for synthesizing hidden phases with unique functional properties and manipulating complex energy landscapes at reduced energy consumption and ultrafast speeds.
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Submitted 7 September, 2025; v1 submitted 15 November, 2024;
originally announced November 2024.
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Solution-phase single-particle spectroscopy for probing multi-polaronic dynamics in quantum emitters at femtosecond resolution
Authors:
Jiaojian Shi,
Yuejun Shen,
Feng Pan,
Weiwei Sun,
Anudeep Mangu,
Cindy Shi,
Amy McKeown-Green,
Parivash Moradifar,
Moungi G. Bawendi,
William E. Moerner,
Jennifer A. Dionne,
Fang Liu,
Aaron M. Lindenberg
Abstract:
The development of many optical quantum technologies depends on the availability of solid-state single quantum emitters with near-perfect optical coherence. However, a standing issue that limits systematic improvement is the significant sample heterogeneity and lack of mechanistic understanding of microscopic energy flow at the single emitter level and ultrafast timescales. Here we develop solutio…
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The development of many optical quantum technologies depends on the availability of solid-state single quantum emitters with near-perfect optical coherence. However, a standing issue that limits systematic improvement is the significant sample heterogeneity and lack of mechanistic understanding of microscopic energy flow at the single emitter level and ultrafast timescales. Here we develop solution-phase single-particle pump-probe spectroscopy with photon correlation detection that captures sample-averaged dynamics in single molecules and/or defect states with unprecedented clarity at femtosecond resolution. We apply this technique to single quantum emitters in two-dimensional hexagonal boron nitride, which suffers from significant heterogeneity and low quantum efficiency. From millisecond to nanosecond timescales, the translation diffusion, metastable-state-related bunching shoulders, rotational dynamics, and antibunching features are disentangled by their distinct photon-correlation timescales, which collectively quantify the normalized two-photon emission quantum yield. Leveraging its femtosecond resolution, spectral selectivity and ultralow noise (two orders of magnitude improvement over solid-state methods), we visualize electron-phonon coupling in the time domain at the single defect level, and discover the acceleration of polaronic formation driven by multi-electron excitation. Corroborated with results from a theoretical polaron model, we show how this translates to sample-averaged photon fidelity characterization of cascaded emission efficiency and optical decoherence time. Our work provides a framework for ultrafast spectroscopy in single emitters, molecules, or defects prone to photoluminescence intermittency and heterogeneity, opening new avenues of extreme-scale characterization and synthetic improvements for quantum information applications.
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Submitted 3 April, 2023;
originally announced April 2023.
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Simons Observatory Microwave SQUID Multiplexing Readout -- Cryogenic RF Amplifier and Coaxial Chain Design
Authors:
Mayuri Sathyanarayana Rao,
Maximiliano Silva-Feaver,
Aamir Ali,
Kam Arnold,
Peter Ashton,
Bradley J. Dober,
Cody J. Duell,
Shannon M. Duff,
Nicholas Galitzki,
Erin Healy,
Shawn Henderson,
Shuay-Pwu Patty Ho,
Jonathan Hoh,
Anna M. Kofman,
Akito Kusaka,
Adrian T. Lee,
Aashrita Mangu,
Justin Mathewson,
Philip Mauskopf,
Heather McCarrick,
Jenna Moore,
Michael D. Niemack,
Christopher Raum,
Maria Salatino,
Trevor Sasse
, et al. (11 additional authors not shown)
Abstract:
The Simons Observatory (SO) is an upcoming polarization-sensitive Cosmic Microwave Background (CMB) experiment on the Cerro Toco Plateau (Chile) with large overlap with other optical and infrared surveys (e.g., DESI, LSST, HSC). To enable the readout of \bigO(10,000) detectors in each of the four telescopes of SO, we will employ the microwave SQUID multiplexing technology. With a targeted multiple…
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The Simons Observatory (SO) is an upcoming polarization-sensitive Cosmic Microwave Background (CMB) experiment on the Cerro Toco Plateau (Chile) with large overlap with other optical and infrared surveys (e.g., DESI, LSST, HSC). To enable the readout of \bigO(10,000) detectors in each of the four telescopes of SO, we will employ the microwave SQUID multiplexing technology. With a targeted multiplexing factor of \bigO{(1,000)}, microwave SQUID multiplexing has never been deployed on the scale needed for SO. Here we present the design of the cryogenic coaxial cable and RF component chain that connects room temperature readout electronics to superconducting resonators that are coupled to Transition Edge Sensor bolometers operating at sub-Kelvin temperatures. We describe design considerations including cryogenic RF component selection, system linearity, noise, and thermal power dissipation.
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Submitted 19 March, 2020;
originally announced March 2020.
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Machine Learning in High Energy Physics Community White Paper
Authors:
Kim Albertsson,
Piero Altoe,
Dustin Anderson,
John Anderson,
Michael Andrews,
Juan Pedro Araque Espinosa,
Adam Aurisano,
Laurent Basara,
Adrian Bevan,
Wahid Bhimji,
Daniele Bonacorsi,
Bjorn Burkle,
Paolo Calafiura,
Mario Campanelli,
Louis Capps,
Federico Carminati,
Stefano Carrazza,
Yi-fan Chen,
Taylor Childers,
Yann Coadou,
Elias Coniavitis,
Kyle Cranmer,
Claire David,
Douglas Davis,
Andrea De Simone
, et al. (103 additional authors not shown)
Abstract:
Machine learning has been applied to several problems in particle physics research, beginning with applications to high-level physics analysis in the 1990s and 2000s, followed by an explosion of applications in particle and event identification and reconstruction in the 2010s. In this document we discuss promising future research and development areas for machine learning in particle physics. We d…
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Machine learning has been applied to several problems in particle physics research, beginning with applications to high-level physics analysis in the 1990s and 2000s, followed by an explosion of applications in particle and event identification and reconstruction in the 2010s. In this document we discuss promising future research and development areas for machine learning in particle physics. We detail a roadmap for their implementation, software and hardware resource requirements, collaborative initiatives with the data science community, academia and industry, and training the particle physics community in data science. The main objective of the document is to connect and motivate these areas of research and development with the physics drivers of the High-Luminosity Large Hadron Collider and future neutrino experiments and identify the resource needs for their implementation. Additionally we identify areas where collaboration with external communities will be of great benefit.
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Submitted 16 May, 2019; v1 submitted 8 July, 2018;
originally announced July 2018.