Magnetoexcitons and Massive Dirac Fermions in Monolayers of Transition Metal Dichalcogenides in a High Magnetic Field

TL;DR

This paper develops a theoretical framework for understanding the emission spectra of magnetoexcitons in monolayer transition metal dichalcogenides under high magnetic fields, revealing how many-body interactions influence optical properties.

Contribution

It introduces an ab initio-parametrized massive Dirac fermion model combined with exact diagonalization to analyze magnetoexciton emission spectra in quantum Hall regimes.

Findings

Emission spectra probe intra-conduction-band excitations.

Many-body interactions cause redshift and broadening.

Results align with recent experimental observations.

Abstract

We present a theory of the emission spectrum of magnetoexcitons interacting with a $\nu = 1$ quantum Hall state of massive Dirac fermions in monolayer transition metal dichalcogenides in high magnetic fields. Using an ab initio-parametrized massive Dirac fermion model including valley and spin degrees of freedom, combined with exact diagonalization techniques, we show that interband emission from the massive Dirac Fermion magnetoexciton interacting with $\nu = 1$ state directly probes intra-conduction-band excitations of the $\nu = 1$. Many-body interactions with the filled massive Dirac fermion $\nu = 1$ level yield a strong renormalization of the emission spectrum, including fully polarized emission, a pronounced redshift, and broadening relative to neutral and charged excitons. The calculated spectra are consistent with recent experiments [1-3], establishing magneto-spectroscopy as a probe of finite carrier densities in massive Dirac systems.