Tunability of the Berry phase in gapped graphene

TL;DR

This paper investigates how the Berry phase in gapped graphene can be continuously tuned by controlling the gap size and doping level, affecting its electronic properties.

Contribution

It demonstrates the gradual change of the Berry phase with gap size and doping, providing a method to tune electronic phases in graphene-based systems.

Findings

Berry phase decreases progressively with increasing gap size.

The phase depends on the Fermi wave vector in doped systems.

Tuning the gap and doping allows continuous control of the Berry phase.

Abstract

When a gap of tunable size opens at the conic band intersections of graphene, the Berry phase does not vanish abruptly, but progressively decreases as the gap increases. The phase depends on the reciprocal-space path radius, i.e., for a doped system, the Fermi wave vector. The phase and its observable consequences can thus be tuned continuously via gap opening --by a modulating potential induced by strain, epitaxy, or nanostructuration-- and doping adjustment.