Electrically tunable orbital coupling and quantum light emission from O-band quantum dot molecules

TL;DR

This paper reports on electrically tunable orbital coupling in InAs/InGaAs quantum dot molecules emitting in the telecom O-band, demonstrating control over excitonic states and single-photon emission properties.

Contribution

It introduces the first demonstration of electrically tunable quantum coupling in O-band quantum dot molecules with implications for quantum light sources.

Findings

Observed anticrossings indicating tunable orbital coupling.

Demonstrated single-photon emission with g(2)(0) = 0.017.

Identified biexciton emission at high pump powers.

Abstract

We present the observation of electrically tunable quantum coupling of orbital states in individual InAs/InGaAs quantum dot molecules emitting in the telecom O-band (~1300 nm). By tuning the static electric field along the growth axis of the QD-molecule, we observe pronounced anticrossings between excitonic transitions and determine the dependence of the interdot electron tunnel coupling on the interdot separation. As the electric field applied along the growth axis of the QD-molecules increases, positively charged exciton complexes sequentially emerge in the time-integrated emission spectra due to electron escape from the system while holes remain trapped. Moreover, for strong pumping, biexciton emission from the O-band molecules is identified. We demonstrate single-photon emission from the InAs/InGaAs QD-molecule emitting around 1300 nm with a g(2)(0) = 0.017(2) and explore the impact of tuning orbital coupling on the second-order correlation function.