Many-body effects on Landau-level spectra and cyclotron resonance in graphene

TL;DR

This paper investigates how many-particle Coulomb interactions influence Landau-level spectra and cyclotron resonance in graphene, revealing electron-hole symmetry and suggesting a small band gap consistent with experimental observations.

Contribution

It provides a theoretical analysis of many-body effects on Landau levels and cyclotron resonance in graphene, incorporating electron-hole symmetry and a possible band gap, aligning with recent experimental data.

Findings

Coulomb interactions significantly affect Landau-level spectra and resonance energies.

Theoretical results support a band gap of approximately 10 meV.

Data reflect underlying electron-hole conjugation symmetry.

Abstract

Recently Russell et al. [Phys. Rev. Lett. 120, 047401 (2018)] have reported a clear signal of many-particle contributions to cyclotron resonance in high-mobility hBN-encapsulated graphene, observing significant variations of resonance energies as a function of the filling factor $\nu$ for a series of interband channels. To elucidate their results, Coulombic contributions to the Landau-level spectra and cyclotron resonance in graphene are examined with a possible band gap taken into account and with emphasis on revealing electron-hole ($eh$) conjugation symmetry underlying such level and resonance spectra. Theory, based on the single-mode approximation, gives a practically good account of the experimental data; the data suggest a band gap of ~ 10 meV and show a profile that apparently reflects $eh$ conjugation symmetry.