Electronic states at twist stacking faults in rhombohedral graphite

TL;DR

This paper investigates how twist stacking faults in rhombohedral graphite create tunable flat electronic bands and topological interface states, revealing potential for novel correlated electronic phenomena.

Contribution

It demonstrates that twist angles can control interface states and flat bands in rhombohedral graphite, combining continuum and tight-binding models for comprehensive analysis.

Findings

Twist angle tunes interface states and flat bands.

Disorder affects layer polarization and Chern number.

Nearly flat bands occur throughout the moiré Brillouin zone.

Abstract

Flat bands in graphitic materials emerged as a platform for realizing tunable correlated physics. As a nodal-line semimetal, rhombohedral graphite features flat drumhead surface states in the vicinity of the Dirac points, which carry a nontrivial topological charge. We present a comprehensive study on rhombohedral graphite with twist stacking faults. Using both the continuum models and the realistic tight-binding models, we show that the twist angle between the graphene layers can tune the interface states at such stacking faults. The evolution of interface states originates from the interplay between the moir\'e periodicity and Zak phase topology, predicting the occurrence of nearly flat bands throughout the moir\'e Brillouin zone. We further investigate the disorder-induced layer polarization and tunable Chern number for flat band, and characterize the relationship between the disorder strength and Chern number in twisted rhombohedral graphite.