Showing 1–8 of 8 results for author: Zong, Z

The substitutional atomic distance model for predicting lattice thermal conductivity in alloys

Authors: Zhicheng Zong, Tianhao Li, Shixian Liu, Haisheng Fang, Nuo Yang

Abstract: Understanding phonon transport in alloys is crucial for the design of high-performance electronic and thermoelectric devices. However, conventional theoretical models fail to provide a clear physical picture of phonon scattering caused by atomic disorder in alloys, and their prediction accuracy is limited. In this work, a new substitutional atomic distance model for alloys is proposed, providing a… ▽ More Understanding phonon transport in alloys is crucial for the design of high-performance electronic and thermoelectric devices. However, conventional theoretical models fail to provide a clear physical picture of phonon scattering caused by atomic disorder in alloys, and their prediction accuracy is limited. In this work, a new substitutional atomic distance model for alloys is proposed, providing an intuitive physical picture. SiGe and InGaAs alloys are taken as representative systems, and their thermal conductivities are calculated, showing good agreement with previous experimental measurements. The results indicate that alloy scattering plays a dominant role in reducing thermal conductivity. This study provides new insights into phonon transport in alloys and offers guidance for tailoring thermal properties through compositional engineering. △ Less

Submitted 28 June, 2026; originally announced June 2026.

3D Ising criticality with Platonic lattice superconducting qubits

Authors: Liyang Sui, Hong-Hao Song, Sainan Huai, Yufan Li, Zhiwen Zong, Kunliang Bu, Xiaopei Yang, Xingrui Liu, Wenyan Jin, Bowen Chen, Xutao Zhang, Jianlan Wu, Yicong Zheng, Shengyu Zhang, Gang v. Chen, Yi Yin

Abstract: The three-dimensional (3D) Ising model is a foundational model in statistical physics and critical phenomena, yet its analytical intractability has long impeded the precise determination of universal critical exponents. While high-precision estimates have been obtained through classical numerical methods and conformal bootstrap techniques, a direct quantum simulation of the 3D Ising criticality re… ▽ More The three-dimensional (3D) Ising model is a foundational model in statistical physics and critical phenomena, yet its analytical intractability has long impeded the precise determination of universal critical exponents. While high-precision estimates have been obtained through classical numerical methods and conformal bootstrap techniques, a direct quantum simulation of the 3D Ising criticality remains challenging, requiring nontrivial connectivity, sufficient system size, and high spectral resolution. In this work, assisted by the state-operator correspondence of conformal field theory, we perform a digital quantum simulation of the 3D Ising critical exponents using a multiply-connected 9-qubit superconducting quantum processor with a Platonic lattice geometry. Employing an extended variational quantum eigensolver equipped with a phase-based loss function, we variationally prepare the low-energy eigenstates of the transverse-field Ising model on a cubic Platonic lattice encoded in an 8-qubit register. The four lowest eigenenergies are extracted via Fourier-transform analysis and high-precision numerical fitting, agreeing with the exact diagonalization values up to +/- 0.001. The resulting scaling dimension Delta_epsilon = 1.5850 and critical exponent nu = 0.7067 match well with theory. △ Less

Submitted 15 June, 2026; originally announced June 2026.

Comments: 19 pages, 11 figures, 5 tables; supplementary information included

Machine learning potential for predicting thermal conductivity of θ-phase and amorphous Tantalum Nitride

Authors: Zhicheng Zong, Yangjun Qin, Jiahong Zhan, Haisheng Fang, Nuo Yang

Abstract: Tantalum nitride (TaN) has attracted considerable attention due to its unique electronic and thermal properties, high thermal conductivity, and applications in electronic components. However, for the θ-phase of TaN, significant discrepancies exist between previous experimental measurements and theoretical predictions. In this study, deep potential models for TaN in both the θ-phase and amorphous p… ▽ More Tantalum nitride (TaN) has attracted considerable attention due to its unique electronic and thermal properties, high thermal conductivity, and applications in electronic components. However, for the θ-phase of TaN, significant discrepancies exist between previous experimental measurements and theoretical predictions. In this study, deep potential models for TaN in both the θ-phase and amorphous phase were developed and employed in molecular dynamics simulations to investigate the thermal conductivities of bulk and nanofilms. The simulation results were compared with reported experimental and theoretical results, and the mechanism for differences were discussed. This study provides insights into the thermal transport mechanisms of TaN, offering guidance for its application in advanced electronic and thermal management devices. △ Less

Submitted 5 August, 2025; originally announced August 2025.

Unveiling the thermal transport mechanism in compressed plastic crystals assisted by deep potential

Authors: Yangjun Qin, Zhicheng Zong, Junwei Che, Tianhao Li, Haisheng Fang, Nuo Yang

Abstract: The unique properties of plastic crystals highlight their potential for use in solid-state refrigeration. However, their practical applications are limited by thermal hysteresis due to low thermal conductivity. In this study, the effect of compressive strain on the thermal transport properties of plastic crystal [(CH3)4N][FeCl4] was investigated using molecular dynamic simulation with a deep neura… ▽ More The unique properties of plastic crystals highlight their potential for use in solid-state refrigeration. However, their practical applications are limited by thermal hysteresis due to low thermal conductivity. In this study, the effect of compressive strain on the thermal transport properties of plastic crystal [(CH3)4N][FeCl4] was investigated using molecular dynamic simulation with a deep neural network potential. It is found that a 9% strain along [001] direction enhances thermal conductivity sixfold. The underlying mechanisms are analyzed through vibrational density of states, spectral energy densities, and mean square displacements. The enhancement in thermal conductivity is primarily due to increased group velocity and reduced phonon scattering, driven by volume compression within the 0-1 THz. These findings offer theoretical insights for the practical application of plastic crystals in thermal management systems. △ Less

Submitted 21 January, 2025; originally announced January 2025.

Using Targeted Phonon Excitation to Modulate Thermal Conductivity of Boron Nitride

Authors: Dongkai Pan, Xiao Wan, Tianhao Li, Zhicheng Zong, Yangjun Qin, Nuo Yang

Abstract: Recent advancements in thermal conductivity modulating strategies have shown promising enhancements to the thermal management capabilities of two-dimensional materials. In this article, both iterative Boltzmann transport equation solution and two-temperature model were employed to investigate the efficacy of targeted phonon excitation applied to hexagonal boron nitride. The results indicate signif… ▽ More Recent advancements in thermal conductivity modulating strategies have shown promising enhancements to the thermal management capabilities of two-dimensional materials. In this article, both iterative Boltzmann transport equation solution and two-temperature model were employed to investigate the efficacy of targeted phonon excitation applied to hexagonal boron nitride. The results indicate significant modifications to hBN's thermal conductivity, achieving increases of up to 30.1% as well as decreases of up to 59.8%. These findings validate the reliability of the strategy, expand its scope of applicability, and establish it as a powerful tool for tailoring thermal properties across a wider range of fields. △ Less

Submitted 20 March, 2025; v1 submitted 4 August, 2023; originally announced August 2023.

Comments: 13 pages, 3 figures

Enhancing interfacial thermal conductance of Si/PVDF by strengthening atomic couplings

Authors: Zhicheng Zong, Shichen Deng, Yangjun Qin, Xiao Wan, Jiahong Zhan, Dengke Ma, Nuo Yang

Abstract: The thermal transport across inorganic/organic interfaces attracts interest for both academic and industry due to its widely applications in flexible electronics etc. Here, the interfacial thermal conductance of inorganic/organic interfaces consisting of silicon and polyvinylidene fluoride is systematically investigated by molecular dynamics simulations. Interestingly, it is demonstrated that a mo… ▽ More The thermal transport across inorganic/organic interfaces attracts interest for both academic and industry due to its widely applications in flexible electronics etc. Here, the interfacial thermal conductance of inorganic/organic interfaces consisting of silicon and polyvinylidene fluoride is systematically investigated by molecular dynamics simulations. Interestingly, it is demonstrated that a modified silicon surface with hydroxyl groups can drastically enhance the conductance by 698%. These results are elucidated based on interfacial couplings and lattice dynamics insights. This study not only provides feasible strategies to effectively modulate the interfacial thermal conductance of inorganic/organic interfaces but also deepens the understanding of the fundamental physics underlying phonon transport across interfaces. △ Less

Submitted 10 June, 2023; v1 submitted 31 May, 2023; originally announced May 2023.

Modulating Thermal Conductivity via Targeted Phonon Excitation

Authors: Xiao Wan, Dongkai Pan, Jing-Tao Lü, Sebastian Volz, Lifa Zhang, Qing Hao, Yangjun Qin, Zhicheng Zong, Nuo Yang

Abstract: Thermal conductivity is a critical material property in numerous applications, such as those related to thermoelectric devices and heat dissipation. Effectively modulating thermal conductivity has become a great concern in the field of heat conduction. In this study, a quantum strategy is proposed to modulate thermal conductivity by exciting targeted phonons. The results show that the thermal cond… ▽ More Thermal conductivity is a critical material property in numerous applications, such as those related to thermoelectric devices and heat dissipation. Effectively modulating thermal conductivity has become a great concern in the field of heat conduction. In this study, a quantum strategy is proposed to modulate thermal conductivity by exciting targeted phonons. The results show that the thermal conductivity of graphene can be tailored in the range of 1559 W/m-K (49%) to 4093 W/m-K (128%), compared with the intrinsic value of 3189 W/m-K. A similar trend is also observed for graphene nanoribbons. The results are obtained through both ab initio calculations and molecular dynamics simulations. This brand-new quantum strategy to modulate thermal conductivity paves a way for quantum heat conduction. △ Less

Submitted 5 April, 2023; v1 submitted 20 September, 2022; originally announced September 2022.

A simultaneous feedback and feed-forward control and its application to realize a random walk on the Bloch sphere in a superconducting Xmon-qubit system

Authors: Liang Xiang, Zhiwen Zong, Zhenhai Sun, Ze Zhan, Ying Fei, Zhangjingzi Dong, Chongxin Run, Zhilong Jia, Peng Duan, Jianlan Wu, Yi Yin, Guoping Guo

Abstract: Measurement-based feedback control is central in quantum computing and precise quantum control. Here we realize a fast and flexible field-programmable-gate-array-based feedback control in a superconducting Xmon qubit system. The latency of room-temperature electronics is custom optimized to be as short as 140 ns. Projective measurement of a signal qubit produces a feedback tag to actuate a conditi… ▽ More Measurement-based feedback control is central in quantum computing and precise quantum control. Here we realize a fast and flexible field-programmable-gate-array-based feedback control in a superconducting Xmon qubit system. The latency of room-temperature electronics is custom optimized to be as short as 140 ns. Projective measurement of a signal qubit produces a feedback tag to actuate a conditional pulse gate to the qubit. In a feed-forward process, the measurement-based feedback tag is brought to a different target qubit for a conditional control. In a two-qubit experiment, the feedback and feed-forward controls are simultaneously actuated in consecutive steps. A quantum number is then generated by the signal qubit, and a random walk of the target qubit is correspondingly triggered and realized on the Bloch sphere. Our experiment provides a conceptually simple and intuitive benchmark for the feedback control in a multi-qubit system. The feedback system can be further scaled up for more complex feedback control experiments. △ Less

Submitted 23 June, 2020; v1 submitted 22 September, 2019; originally announced September 2019.

Journal ref: Phys. Rev. Applied 14, 014099 (2020)