Surface effects in a semiconductor photonic nanowire and spectral stability of an embedded single quantum dot

TL;DR

This study investigates how surface effects in GaAs photonic nanowires influence the spectral stability of embedded InAs quantum dots, identifying causes of emission drift and methods to suppress it for quantum optics applications.

Contribution

The paper demonstrates that surface treatment can effectively suppress emission energy drift in quantum dots within nanowires, improving spectral stability for quantum photonic devices.

Findings

Surface effects cause emission energy drift in quantum dots.

Oxygen molecule sticking modifies surface charge and electric field.

Proper surface treatment suppresses spectral drift.

Abstract

We evidence the influence of surface effects for InAs quantum dots embedded into GaAs photonic nanowires used as efficient single photon sources. We observe a continuous temporal drift of the emission energy that is an obstacle to resonant quantum optics experiments at the single photon level. We attribute the drift to the sticking of oxygen molecules onto the wire, which modifies the surface charge and hence the electric field seen by the quantum dot. The influence of temperature and excitation laser power on this phenomenon is studied. Most importantly, we demonstrate a proper treatment of the nanowire surface to suppress the drift.