Magneto-optical Selection Rules in Bilayer Bernal Graphene

TL;DR

This paper investigates the magneto-optical properties of bilayer Bernal graphene using a tight-binding model, revealing complex selection rules, absorption features, and differences from monolayer graphene due to interlayer interactions.

Contribution

It provides a detailed analysis of the magneto-optical selection rules and absorption spectra in bilayer Bernal graphene considering key interlayer interactions, which was not comprehensively studied before.

Findings

Identification of two groups of Landau levels based on wave function characteristics.

Four categories of absorption peaks with complex selection rules.

Distinct absorption features compared to monolayer graphene due to interlayer effects.

Abstract

The low-frequency magneto-optical properties of bilayer Bernal graphene are studied by the tight-binding model with four most important interlayer interactions taken into account. Since the main features of the wave functions are well depicted, the Landau levels can be divided into two groups based on the characteristics of the wave functions. These Landau levels lead to four categories of absorption peaks in the optical absorption spectra. Such absorption peaks own complex optical selection rules and these rules can be reasonably explained by the characteristics of the wave functions. In addition, twin-peak structures, regular frequency-dependent absorption rates and complex field-dependent frequencies are also obtained in this work. The main features of the absorption peaks are very different from those in monolayer graphene and have their origin in the interlayer interactions.