Subnanosecond spectral diffusion of a single quantum dot in a nanowire

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., Nat. Photon. 4, 696 (2010)] that offers subnanosecond resolution. These data are consistent with a model where only a single carrier wanders around in traps located in the vicinity of the quantum dot.