Effective theory of rotationally faulted multilayer graphene - the local limit

TL;DR

This paper develops an effective Dirac model with space-dependent mass to describe interlayer coupling effects in rotationally faulted multilayer graphene, providing insights into localization and velocity renormalization phenomena.

Contribution

It introduces a local limit of the theory for large interlayer bias, enabling analysis of localization and velocity effects in twisted graphene bilayers.

Findings

Agreement with experimental results in magnetic fields

Predictions of localization phenomena at zero magnetic field

Insights into velocity renormalization in twisted bilayers

Abstract

Interlayer coupling in rotationally faulted graphene multilayers breaks the local sublattice-symmetry of the individual layers. Earlier we have presented a theory of this mechanism, which reduces to an effective Dirac model with space-dependent mass in an important limit. It thus makes a wealth of existing knowledge available for the study of rotationally faulted graphene multilayers. Agreement of this theory with a recent experiment in a strong magnetic field was demonstrated. Here we explore some of the predictions of this theory for the system in zero magnetic field at large interlayer bias, when it becomes local in space. We use that theory to illuminate the physics of localization and velocity renormalization in twisted graphene bilayers.