arXiv subjects

C. Zinoni

Publications and source records attributed to C. Zinoni.

3 recordsLinked to original sources

arXiv2009

Controlling the charge environment of single quantum dots in a photonic-crystal cavity

We demonstrate that the presence of charge around a semiconductor quantum dot (QD) strongly affects its optical properties and produces non-resonant coupling to the modes of a microcavity. We first show that, besides (multi)exciton lines, a QD generates a spectrally broad emission which efficiently couples to cavity modes. Its temporal dynamics shows that it is related to the Coulomb interaction between the QD (multi)excitons and carriers in the adjacent wetting layer. This mechanism can be suppressed by the application of an electric field, making the QD closer to an ideal two-level system.

cond-mat.mes-hall↗

arXiv2006

Single photonics at telecom wavelengths using nanowire superconducting detectors

Single photonic applications - such as quantum key distribution - rely on the transmission of single photons, and require the ultimate sensitivity that an optical detector can achieve. Single-photon detectors must convert the energy of an optical pulse containing a single photon into a measurable electrical signal. We report on fiber-coupled superconducting single-photon detectors (SSPDs) with specifications that exceed those of avalanche photodiodes (APDs), operating at telecommunication wavelength, in sensitivity, temporal resolution and repetition frequency. The improved performance is demonstrated by measuring the intensity correlation function g(2)(t) of single-photon states at 1300nm produced by single semiconductor quantum dots (QDs).

physics.ins-det↗

arXiv2006

Time resolved measurements on low-density single quantum dots at 1300nm

We present time integrated and time resolved measurements on single In/As quantum dots (QD) emitting at 1300nm, at 10K, embedded in a planar microcavity. We clearly identify a standard spectroscopic signature from single QDs and compare the exciton line width and biexciton (BX) binding energy for several QDs. We present this data for QDs spatially selected by etched mesas and metallic apertures. Time resolved photoluminescence (PL) from single electron-hole recombination in the ground state of the QD is investigated as a function of excitation power and temperature. The measurements reveal the presence of a background emission that delays the PL of excitons in the ground state.

cond-mat.other↗