Charge-sensing of a Ge/Si core/shell nanowire double quantum dot using a high-impedance superconducting resonator

Spin qubits in germanium are a promising contender for scalable quantum computers. Reading out of the spin and charge configuration of quantum dots formed in Ge/Si core/shell nanowires is typically performed by measuring the current through the nanowire. Here, we demonstrate a more versatile approach on investigating the charge configuration...

Crystal Phase Quantum Well Emission with Digital Control

One of the major challenges in the growth of quantum well and quantum dot heterostructures is the realization of atomically sharp interfaces. Nanowires provide a new opportunity to engineer the band structure as they facilitate the controlled switching of the crystal structure between the zinc-blende (ZB) and wurtzite (WZ) phases. Such a...

Spontaneous emission control of single quantum dots in bottom-up nanowire waveguides

Nanowire waveguides with controlled shape are promising for engineering the collection efficiency of quantum light sources. We investigate the exciton lifetime in individual InAsP quantum dots, perfectly positioned on-axis of InP nanowire waveguides. We demonstrate control over the quantum dot spontaneous emission by varying the nanowire...

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,...

Quantum optics with single nanowire quantum dots

In this paper we present our recent developments in control and manipulation of individual spins and photons in a single nanowire quantum dot. Specific examples include demonstration of optical excitation of single spin states, charge tunable quantum devices and single photon sources. We will also discuss our recent discovery of a new type of...

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...