Polarization-dependent interference between dipole moments of a resonantly excited quantum dot

TL;DR

This paper investigates how polarization affects the interference of dipole moments in a resonantly excited quantum dot, revealing the role of coherence and interference in its optical response.

Contribution

It introduces a polarization-dependent RPLE measurement and a 3-level quantum model to analyze interference effects in quantum dot exciton states.

Findings

Interference between exciton states depends on detection polarization.

Coherence between exciton states can be extracted from spectra.

Model agrees well with experimental data.

Abstract

Resonant photoluminescence excitation (RPLE) spectra of a neutral InGaAs quantum dot show an unconventional line-shape that depends on the detection polarization. We characterize this phenomenon by performing polarization-dependent RPLE measurements and simulating the measured spectra with a 3-level quantum model. This analysis enables us to extract the coherence between the two exciton states from the measured spectra. The good agreement between the data and model indicates that the interference between coherent scatterings from both fine structure split exciton states is the key to understanding this phenomenon.