Interplay between hyperfine and anisotropic exchange interactions in exciton luminescence of quantum dots

TL;DR

This paper theoretically investigates how hyperfine and anisotropic exchange interactions influence exciton luminescence in quantum dots, focusing on polarization behaviors under magnetic fields in a specific interaction regime.

Contribution

It introduces a detailed theoretical analysis of exciton polarization dependencies considering the interplay of hyperfine and anisotropic exchange interactions in quantum dots.

Findings

Polarization degrees depend on external magnetic field.

Hyperfine interaction energy is comparable to anisotropic exchange splitting.

Theoretical predictions of polarization behavior under resonant excitation.

Abstract

The optical orientation and alignment of excitons in semiconductor indirect gap quantum dots have been studied theoretically. A special regime is analyzed in which the energy of the hyperfine interaction of an electron with lattice nuclei is small compared to the exchange splitting between bright and dark excitonic levels, but is comparable to the anisotropic exchange splitting of the radiative doublet. The dependencies of degrees of circular and linear polarization on the external magnetic field under resonant excitation of excitons by polarized light are calculated.