Generation of a fully valley-polarized current in bulk graphene

TL;DR

This paper demonstrates a method to generate a fully valley-polarized current in bulk graphene using a strained, magnetically modulated device, with tunable properties and measurable valley polarization.

Contribution

It introduces a novel strained graphene device with magnetic superlattice to produce and control fully valley-polarized currents in bulk graphene.

Findings

Achieves a bulk fully valley-polarized current in graphene.

The device's valley polarization can be tuned by structural parameters.

A valley-resolved Hall setup measures the polarization degree.

Abstract

The generation of a fully valley-polarized current (FVPC) in bulk graphene is a fundamental goal in valleytronics. To this end, we investigate valley-dependent transport through a strained graphene modulated by a finite magnetic superlattice. It is found that this device allows a coexistence of insulating transmission gap of one valley and metallic resonant band of the other. Accordingly, a substantial bulk FVPC appears in a wide range of edge orientation and temperature, which can be effectively tuned by structural parameters. A valley-resolved Hall configuration is designed to measure the valley polarization degree of the filtered current.