Strongly enhanced nonlinear acoustic valley Hall effect in tilted Dirac materials

Fuente: arXiv
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Hauptverfasser: Wan, Jia-Liang, Wu, Ying-Li, Chen, Ke-Qiu, Yu, Xiao-Qin
Format: Preprint
Veröffentlicht: 2024
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author Wan, Jia-Liang
Wu, Ying-Li
Chen, Ke-Qiu
Yu, Xiao-Qin
author_facet Wan, Jia-Liang
Wu, Ying-Li
Chen, Ke-Qiu
Yu, Xiao-Qin
contents It has been recently established that a nonlinear valley current could be generated through traveling a surface acoustic wave (SAW) in two-dimensional Dirac materials. So far, the SAW-driven valley currents have been attributed to warping Fermi surface or Berry phase effect. Here, we demonstrate that tilt mechanism can also lead to a nonlinear valley Hall current (VHC) when propagating SAW in materials with the tilted Dirac cone placed on a piezoelectric substrate. It's found that the nonlinear VHC exhibits a $\sinθ$ dependence on the orientation of tilt with respect to SAW. In addition, this tilt-induced nonlinear acoustic VHC shows independence on the relaxation time, distinguishing from the contributions from the Berry phase or trigonal warping. Remarkably, the magnitude of the nonlinear acoustic VHC from tilt mechanism in the uniaxially strained graphene is two orders larger than those reported in MoS$_2$ stemmed from the Berry phase effect and the warping effect.
format Preprint
id arxiv_https___arxiv_org_abs_2403_01073
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Strongly enhanced nonlinear acoustic valley Hall effect in tilted Dirac materials
Wan, Jia-Liang
Wu, Ying-Li
Chen, Ke-Qiu
Yu, Xiao-Qin
Mesoscale and Nanoscale Physics
It has been recently established that a nonlinear valley current could be generated through traveling a surface acoustic wave (SAW) in two-dimensional Dirac materials. So far, the SAW-driven valley currents have been attributed to warping Fermi surface or Berry phase effect. Here, we demonstrate that tilt mechanism can also lead to a nonlinear valley Hall current (VHC) when propagating SAW in materials with the tilted Dirac cone placed on a piezoelectric substrate. It's found that the nonlinear VHC exhibits a $\sinθ$ dependence on the orientation of tilt with respect to SAW. In addition, this tilt-induced nonlinear acoustic VHC shows independence on the relaxation time, distinguishing from the contributions from the Berry phase or trigonal warping. Remarkably, the magnitude of the nonlinear acoustic VHC from tilt mechanism in the uniaxially strained graphene is two orders larger than those reported in MoS$_2$ stemmed from the Berry phase effect and the warping effect.
title Strongly enhanced nonlinear acoustic valley Hall effect in tilted Dirac materials
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2403.01073