Resonant Tunneling and Intrinsic Bistability in Twisted Graphene Structures

TL;DR

This paper predicts that twisted graphene heterostructures can exhibit intrinsic bistability in their current-voltage characteristics due to resonant tunneling and charge coupling, enabling fast switching in nanoscale devices.

Contribution

It introduces a novel bistability mechanism in twisted graphene structures based on resonant tunneling and charge interactions, with a simple trilayer model.

Findings

Bistability arises from resonant tunneling and interlayer charge coupling.

Bistability can be controlled by geometric device parameters.

Fast switching times are possible due to nanoscale architecture.

Abstract

We predict that vertical transport in heterostructures formed by twisted graphene layers can exhibit a unique bistability mechanism. Intrinsically bistable $I$-$V$ characteristics arise from resonant tunneling and interlayer charge coupling, enabling multiple stable states in the sequential tunneling regime. We consider a simple trilayer architecture, with the outer layers acting as the source and drain and the middle layer floating. Under bias, the middle layer can be either resonant or non-resonant with the source and drain layers. The bistability is controlled by geometric device parameters easily tunable in experiments. The nanoscale architecture can enable uniquely fast switching times.