Two-dimensional magnetoexcitons in the presence of spin-orbit coupling

TL;DR

This paper theoretically investigates how spin-orbit coupling influences magnetoexcitons in quantum wells under strong magnetic fields, revealing tunable spectral features and anisotropic energy dispersion that could enable optical measurement of spin-orbit parameters.

Contribution

It introduces a theoretical framework for understanding spin-orbit effects on magnetoexcitons, including spectral splitting and anisotropy, with potential for experimental parameter extraction.

Findings

Double-peak structure in absorption spectrum due to hybridization.

Splitting magnitude tunable by in-plane magnetic field orientation.

Anisotropic exciton energy dispersion caused by spin-orbit and Coulomb interactions.

Abstract

We study theoretically the effect of spin-orbit coupling on quantum well excitons in a strong magnetic field. We show that, in the presence of an in-plane field component, the excitonic absorption spectrum develops a double-peak structure due to hybridization of bright and dark magnetoexcitons. If the Rashba and Dresselhaus spin-orbit constants are comparable, the magnitude of splitting can be tuned in a wide interval by varying the azimuthal angle of the in-plane field. We also show that the interplay between spin-orbit and Coulomb interactions leads to an anisotropy of exciton energy dispersion in the momentum plane. The results suggest a way for direct optical measurements of spin-orbit parameters.