Band-selective simulation of photoelectron intensity and converging Berry phase in trilayer graphene

TL;DR

This study uses band-selective simulations to explore how the Berry phase in trilayer graphene varies with energy, revealing energy-dependent Berry phase changes linked to band hybridization, which could enable tuning of quantum phenomena.

Contribution

It introduces a band-selective simulation approach for Berry phase analysis in trilayer graphene, highlighting energy-dependent Berry phase variations in ABA-stacked structures.

Findings

ABC- and ABA-stacked trilayer graphene show characteristic rotational angles.

Berry phase in ABA-stacked graphene varies with binding energy.

Hybridization at band touching points affects Berry phase behavior.

Abstract

Berry phase is one of the key elements to understand quantum-mechanical phenomena such as the Aharonov-Bohm effect and the unconventional Hall effect in graphene. The Berry phase in monolayer and bilayer graphene has been manifested by the anisotropic distribution of photoelectron intensity along a closed loop in the momentum space as well as its rotation by a characteristic angle upon rotating light polarization. Here we report the band-selective simulation of photoelectron intensity of trilayer graphene to understand its Berry phase within the tight-binding formalism. ABC- and ABA-stacked trilayer graphene show characteristic rotational angles of photoelectron intensity distribution, as predicted from their well-known Berry phases. Surprisingly, however, in ABA-stacked trilayer graphene, the rotational angle changes upon approaching toward the band touching point between the conduction and valence bands, which suggest that Berry phase changes as a function of binding energy. The binding energy-dependent Berry phase is attributed to the enhanced hybridization of the two electron bands of ABA-stacked trilayer graphene that converge at the band touching point, resulting in the converging Berry phase. These findings will provide an efficient way of tuning Berry phase and hence exotic phenomena stemming from the Berry phase.