Photon statistics from coupled quantum dots

TL;DR

This paper investigates photon emission from coupled quantum dots, revealing the nature of their interaction mechanisms, primarily dipole-dipole coupling and phonon-assisted energy transfer, through optical measurements.

Contribution

It provides experimental evidence of coupling mechanisms in closely-spaced quantum dots, aligning with recent theoretical predictions.

Findings

Evidence of quantum dot coupling through photon correlations

Suppression of tunneling between nonidentical dots

Dominance of dipole-dipole and phonon-assisted interactions

Abstract

We present an optical study of closely-spaced self-assembled InAs/GaAs quantum dots. The energy spectrum and correlations between photons subsequently emitted from a single pair provide not only clear evidence of coupling between the quantum dots but also insight into the coupling mechanism. Our results are in agreement with recent theories predicting that tunneling is largely suppressed between nonidentical quantum dots and that the interaction is instead dominated by dipole-dipole coupling and phonon-assisted energy transfer processes.