Full Slonczewski-Weiss-McClure parametrization of few-layer twistronic graphene

TL;DR

This paper develops a comprehensive model for describing interlayer coupling in few-layer twistronic graphene using the full Slonczewski-Weiss-McClure parametrization, refining existing models and analyzing their effects on electronic properties.

Contribution

It introduces a hybrid k dot p - tight binding model based on the full SWMcC Hamiltonian to accurately describe interlayer interactions in twisted and Bernal graphene structures.

Findings

Full SWMcC parametrization refines the minimal model for twisted interfaces.

Electron-hole asymmetry appears in twisted bilayers due to additional terms.

Subtle changes in moire miniband spectra in multilayer graphene confirm minimal model's broad applicability.

Abstract

We use a hybrid k dot p theory - tight binding (HkpTB) model to describe interlayer coupling simultaneously in both Bernal and twisted graphene structures. For Bernal-aligned interfaces, HkpTB is parametrized using the full Slonczewski-Weiss-McClure (SWMcC) Hamiltonian of graphite, which is then used to refine the commonly used minimal model for twisted interfaces, by deriving additional terms that reflect all details of the full SWMcC model of graphite. We find that these terms introduce some electron-hole asymmetry in the band structure of twisted bilayers, but in twistronic multilayer graphene, they produce only a subtle change of moire miniband spectra, confirming the broad applicability of the minimal model for implementing the twisted interface coupling in such systems.