Journal Article

Transform-limited single photons from a single quantum dot

Warburton, Richard J., Ludwig, Arne, Wieck, Andreas D., Kuhlmann, Andreas V., Houel, Julien, Reuter, Dirk, Prechtel, Jonathan H.

2015

Overview

Developing a quantum photonics network requires a source of very-high-fidelity single photons. An outstanding challenge is to produce a transform-limited single-photon emitter to guarantee that single photons emitted far apart in the time domain are truly indistinguishable. This is particularly difficult in the solid-state as the complex environment is the source of noise over a wide bandwidth. A quantum dot is a robust, fast, bright and narrow-linewidth emitter of single photons; layer-by-layer growth and subsequent nano-fabrication allow the electronic and photonic states to be engineered. This represents a set of features not shared by any other emitter but transform-limited linewidths have been elusive. Here, we report transform-limited linewidths measured on second timescales, primarily on the neutral exciton but also on the charged exciton close to saturation. The key feature is control of the nuclear spins, which dominate the exciton dephasing via the Overhauser field. Photons emitted from a quantum dot typically have slightly different frequencies owing to various sources of noise. Here, the authors suppress the noise, notably the noise arising from the nuclear spins, and demonstrate single-photon emission with a transform-limited optical linewidth.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Pub. Group
• Subject: 140/125 / 639/301/357/1017 / 639/624/400/1105 / 639/624/400/3925 / 639/925 / Chemical Sciences / Emitters / Engineering Sciences / Excitons / Fabrication / Humanities and Social Sciences / multidisciplinary / Photonics / Photons / Physics / Quantum dots / Science / Science (multidisciplinary)