Influence of electric fields on absorption spectra of AAB-stacked trilayer graphene

TL;DR

This study investigates how electric fields influence the absorption spectra of AAB-stacked trilayer graphene, revealing changes in optical properties and excitation channels through theoretical calculations.

Contribution

It provides a detailed theoretical analysis of the effects of electric fields on the optical absorption spectra of AAB-stacked trilayer graphene, highlighting the impact on excitation channels and spectral features.

Findings

Electric fields alter the absorption spectra of AAB-stacked trilayer graphene.

Different excitation transitions can disappear due to velocity metric contributions.

Electric field strength affects the frequency and presence of absorption structures.

Abstract

The band structures and optical properties of AAB-stacked trilayer graphenes (AAB-TLG) are calculated by the tight-binding model and gradient approximation. Three pairs of the energy bands exhibit very different energy dispersions at low energy and saddle points at the middle energy. At zero electric field, $3$$^2$ excitation channels exist in both the low and middle frequencies, and cause the very rich joint density of states (JDOS). However, the structures in the JDOS do not appear in the absorption spectra completely. Due to the different contributions from the velocity metric elements, some excitation transitions disappear in the spectra. Furthermore, the frequency and the existence of the absorption structures are affected by the increase of the electric field from zero.