Effects of Coulomb interactions on the splitting of luminescence lines

TL;DR

This paper investigates how Coulomb interactions influence the splitting of circularly polarized luminescence lines in quantum dots, revealing additional contributions beyond Zeeman and Overhauser effects, especially in odd electron-hole pair cases.

Contribution

It provides new insights into Coulomb interaction effects on luminescence line splitting in quantum dots under specific excitation conditions.

Findings

Coulomb interactions contribute a few meV to the splitting.

Shell-filling signatures are observable in the splitting.

Splitting behavior differs between even and odd electron-hole pair populations.

Abstract

We study the splitting between the right-hand and left-hand circularly polarized luminescence lines in a quantum dot under relatively weak confinement regime and resonant high-power excitation. When the dot is populated with an even number of electron-hole pairs (biexciton and higher excitations), the splitting measures basically the Zeeman energy. However, in the odd number of pairs case, we have, in addition to the Zeeman and Overhauser shifts, a contribution to the splitting coming from Coulomb interactions. This contribution is of the order of a few meV, and shows distinct signatures of shell-filling in the quantum dot.