Subnanosecond spectral diffusion of a single quantum dot in a nanowire

TL;DR

This study investigates the rapid spectral diffusion of a single quantum dot in a nanowire, revealing that a single carrier wandering near the dot causes the diffusion, with measurements spanning various powers and temperatures.

Contribution

It introduces a subnanosecond resolution technique to measure spectral diffusion and models the process as caused by a single carrier in nearby traps.

Findings

Spectral diffusion time varies with pumping power and temperature.

Diffusion is consistent with a model involving a single wandering carrier.

The technique provides high temporal resolution for quantum dot studies.

Abstract

We have studied spectral diffusion of the photoluminescence of a single CdSe quantum dot inserted in a ZnSe nanowire. We have measured the characteristic diffusion time as a function of pumping power and temperature using a recently developed technique [G. Sallen et al, Nature Photon. \textbf{4}, 696 (2010)] that offers subnanosecond resolution. These data are consistent with a model where only a \emph{single} carrier wanders around in traps located in the vicinity of the quantum dot.