Single quantum dot nanowire photodetectors

We report InP nanowire photodetectors with a single InAsP quantum dot as light absorbing element. With excitation above the InP band gap, the nanowire photodetectors are efficient (quantum efficiency of 4%). Under resonant excitation of the quantum dot, the photocurrent amplitude depends on the linear polarization direction of the incident light...

Surround-gated vertical nanowire quantum dots

We report voltage dependent photoluminescence experiments on single indium arsenide phosphide (InAsP) quantum dots embedded in vertical surround-gated indium phosphide (InP) nanowires. We show that by tuning the gate voltage, we can access different quantum dot charge states. We study the anisotropic exchange splitting by polarization analysis,...

Diameter-dependent conductance of InAs nanowires

Electrical conductance through InAs nanowires is relevant for electronic applications as well as for fundamental quantum experiments. Here, we employ nominally undoped, slightly tapered InAs nanowires to study the diameter dependence of their conductance. By contacting multiple sections of each wire, we can study the diameter dependence within...

Ultrasmall silicon quantum dots

We report the realization of extremely small single quantum dots in p-type silicon nanowires, defined by Schottky tunnel barriers with Ni and NiSi contacts. Despite their ultrasmall size the NiSi–Si–NiSi nanowire quantum dots readily allow spectroscopy of at least ten consecutive holes, and additionally they display a pronounced excited-state...