中国科学:物理学 力学 天文学(英文版)2024,Vol.67Issue(8) :153-158.DOI:10.1007/s11433-024-2404-0

Purity-dependent Lorenz number,electron hydrodynamics and electron-phonon coupling in WTe2

Wei Xie Feng Yang Liangcai Xu Xiaokang Li Zengwei Zhu Kamran Behnia
中国科学:物理学 力学 天文学(英文版)2024,Vol.67Issue(8) :153-158.DOI:10.1007/s11433-024-2404-0

Purity-dependent Lorenz number,electron hydrodynamics and electron-phonon coupling in WTe2

Wei Xie 1Feng Yang 1Liangcai Xu 1Xiaokang Li 1Zengwei Zhu 1Kamran Behnia2
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作者信息

  • 1. Wuhan National High Magnetic Field Center and School of Physics,Huazhong University of Science and Technology,Wuhan 430074,China
  • 2. Laboratoire de Physique et d'Étude des Matériaux(ESPCI-CNRS-Sorbonne Université)PSL University,Paris 75005,France
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Abstract

We present a study of electrical and thermal transport in Weyl semimetal WTe2 down to 0.3 K.The Wiedemann-Franz law holds below 2 K and a downward deviation starts above.The deviation is more pronounced in cleaner samples,as expected in the hy-drodynamic picture of electronic transport,where a fraction of electron-electron collisions conserve momentum.Phonons are the dominant heat carriers and their mean-free-path does not display a Knudsen minimum.This is presumably a consequence of weak anharmonicity,as indicated by the temperature dependence of the specific heat.Frequent momentum exchange between phonons and electrons leads to quantum oscillations of the phononic thermal conductivity.Bloch-Grüneisen picture of electron-phonon scattering breaks down at low temperature when Umklapp ph-ph collisions cease to be a sink for electronic flow of momentum.Comparison with semi-metallic Sb shows that normal ph-ph collisions are amplified by anharmonicity.In both semimetals,at cryogenic temperature,e-ph collisions degrade the phononic flow of energy but not the electronic flow of momentum.

Key words

thermal conductivity/Wiedemann-Franz law/electron hydrodynamics/electron-phonon coupling

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基金项目

National Key Research and Development Program of China(2022YFA1403500)

National Science Foundation of China(12004123)

National Science Foundation of China(51861135104)

National Science Foundation of China(11574097)

Fundamental Research Funds for the Central Universities(2019kfyXMBZ071)

Agence Nationale de la Recherche(ANR-19-CE30-0014-04)

China National Postdoctoral Program for Innovative Talents(BX20200143)

China Postdoctoral Science Foundation(2020M682386)

出版年

2024
中国科学:物理学 力学 天文学(英文版)
中国科学院

中国科学:物理学 力学 天文学(英文版)

CSTPCD
影响因子:0.91
ISSN:1674-7348
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