All-strain based valley filter in graphene nanoribbons using snake states

TL;DR

This paper proposes a strain-engineered valley filter in graphene nanoribbons utilizing snake states induced by pseudo-magnetic fields, enabling valley polarization without external magnetic fields.

Contribution

It introduces a novel all-strain based valley filtering mechanism in graphene nanoribbons using snake states, optimizing stress distribution for enhanced valley polarization.

Findings

Strain-induced pseudo-magnetic fields create valley-polarized snake states.

Adjusting stress distribution maximizes valley filtering.

The method enables valley filtering solely through strain engineering.

Abstract

A pseudo-magnetic field kink can be realized along a graphene nanoribbon using strain engineering. Electron transport along this kink is governed by snake states that are characterized by a single propagation direction. Those pseudo-magnetic fields point towards opposite directions in the K and K' valleys, leading to valley polarized snake states. In a graphene nanoribbon with armchair edges this effect results in a valley filter that is based only on strain engineering. We discuss how to maximize this valley filtering by adjusting the parameters that define the stress distribution along the graphene ribbon.