Generation of pure bulk valley current in graphene

TL;DR

This paper proposes a practical method to generate and detect pure bulk valley currents in graphene using adiabatic strain and chemical potential modulations, advancing the field of graphene valleytronics.

Contribution

It introduces a novel scheme for bulk valley current generation in graphene via cyclic strain and chemical potential deformations, enabling all-electrical detection.

Findings

Valley current can be generated through strain-induced gauge fields.

The scheme breaks mirror symmetry within valleys, enabling quantum pumping.

A detection setup for pure valley currents is proposed.

Abstract

The generation of valley current is a fundamental goal in graphene valleytronics but no practical ways of its realization are known yet. We propose a workable scheme for the generation of bulk valley current in a graphene mechanical resonator through adiabatic cyclic deformations of the strains and chemical potential in the suspended region. The accompanied strain gauge fields can break the spatial mirror symmetry of the problem within each of the two inequivalent valleys, leading to a fnite valley current due to quantum pumping. An all-electrical measurement configuration is designed to detect the novel state with pure bulk valley currents.