Nonlinear Valley Hall Effect

Fuente: arXiv
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Main Authors: Das, Kamal, Ghorai, Koushik, Culcer, Dimitrie, Agarwal, Amit
Format: Preprint
Published: 2023
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_version_ 1866917902649655296
author Das, Kamal
Ghorai, Koushik
Culcer, Dimitrie
Agarwal, Amit
author_facet Das, Kamal
Ghorai, Koushik
Culcer, Dimitrie
Agarwal, Amit
contents The valley Hall effect arises from valley contrasting Berry curvature and requires inversion symmetry breaking. Here, we propose a nonlinear mechanism to generate a valley Hall current in systems with both inversion and time-reversal symmetry, where the linear and second-order charge Hall currents vanish along with the linear valley Hall current. We show that a second-order valley Hall signal emerges from the electric field correction to the Berry curvature, provided a valley-contrasting anisotropic dispersion is engineered. We demonstrate the nonlinear valley Hall effect in tilted massless Dirac fermions in strained graphene and organic semiconductors. Our work opens up the possibility of controlling the valley degree of freedom in inversion symmetric systems via nonlinear valleytronics.
format Preprint
id arxiv_https___arxiv_org_abs_2307_12088
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Nonlinear Valley Hall Effect
Das, Kamal
Ghorai, Koushik
Culcer, Dimitrie
Agarwal, Amit
Mesoscale and Nanoscale Physics
Materials Science
The valley Hall effect arises from valley contrasting Berry curvature and requires inversion symmetry breaking. Here, we propose a nonlinear mechanism to generate a valley Hall current in systems with both inversion and time-reversal symmetry, where the linear and second-order charge Hall currents vanish along with the linear valley Hall current. We show that a second-order valley Hall signal emerges from the electric field correction to the Berry curvature, provided a valley-contrasting anisotropic dispersion is engineered. We demonstrate the nonlinear valley Hall effect in tilted massless Dirac fermions in strained graphene and organic semiconductors. Our work opens up the possibility of controlling the valley degree of freedom in inversion symmetric systems via nonlinear valleytronics.
title Nonlinear Valley Hall Effect
topic Mesoscale and Nanoscale Physics
Materials Science
url https://arxiv.org/abs/2307.12088