Graphene nanodrums as valleytronic devices

TL;DR

This paper explores graphene nanodrums as valleytronic devices, demonstrating their ability to act as efficient valley polarizers and filters through strain-induced pseudomagnetic fields, with potential applications in electron beam control.

Contribution

It introduces the use of graphene nanodrums as valleytronic devices leveraging strain-induced pseudomagnetic fields, a novel approach in electronic transport control.

Findings

Graphene nanodrums can polarize and filter valley currents with small strains.

The devices work for both ballistic and dispersed electron beams.

Semiclassical trajectories effectively predict device functionality.

Abstract

We investigate the electronic transport in graphene nanoelectromechanical resonators (GrNEMS), known also as graphene nanodrums or nanomembranes. We demonstrate that these devices, despite small values of out-of-plane strain, between $0.1$ and $1\%$, can be used as efficient and robust valley polarizers and filters. Their working principle is based on the pseudomagnetic field generated by the strain of the graphene membrane. They work for ballistic electron beams as well as for strongly dispersed ones and can be also used as electron beam collimators due to the focusing effect of the pseudomagnetic field. We show additionally that the current flow can be estimated by semiclassical trajectories which represent a computationally efficient tool for predicting the functionality of the devices.