Theory of In-Plane-Magnetic-Field-Dependent Excitonic Spectra in Atomically Thin Semiconductors

TL;DR

This paper provides a theoretical analysis of how in-plane magnetic fields affect excitonic spectra in atomically thin semiconductors, revealing hybridization effects that alter spectral features and exciton brightness.

Contribution

It introduces a theoretical framework for understanding magnetic field-induced hybridization between bright and dark excitons in TMDC monolayers, highlighting spectral modifications.

Findings

In-plane magnetic fields induce hybridization between bright and dark excitons.

Spectral features such as energy shifts and broadening are analytically characterized.

Dark excitons can become optically brightened under magnetic fields.

Abstract

The linear absorption spectrum of excitons in TMDC monolayers under the influence of an in-plane magnetic field is theoretically studied. We demonstrate that in-plane magnetic fields induce a hybridization between spin-bright and spin-dark exciton transitions, resulting in a brightening of spin-dark excitons. We analytically investigate spectral features including resonance energy shifts, broadening and amplitudes ratios. In particular, for a MoSe$_2$ monolayer with radiatively-limited linewidth, we find a complex interplay of dark-bright splitting and linewidth difference of both involved spin-bright and spin-dark excitons.