A single-photon emitter coupled to a phononic-crystal resonator in the resolved-sideband regime.

A promising route towards the deterministic creation and annihilation of single-phonons is to couple a single-photon emitter to a mechanical resonator. The challenge lies in reaching the resolved-sideband regime with a large coupling rate and a high mechanical quality factor. We achieve this by coupling self-assembled InAs quantum dots to a small mode-volume phononic-crystal resonator with mechanical frequency Ω/2π = 1.

Enhanced Electron-Spin Coherence in a GaAs Quantum Emitter.

A spin-photon interface should operate with both coherent photons and a coherent spin to enable cluster-state generation and entanglement distribution. In high-quality devices, self-assembled GaAs quantum dots are near-perfect emitters of on-demand coherent photons. However, the spin rapidly decoheres via the magnetic noise arising from the host nuclei.

Quantum interference of identical photons from remote GaAs quantum dots.

Photonic quantum technology provides a viable route to quantum communication, quantum simulation and quantum information processing. Recent progress has seen the realization of boson sampling using 20 single photons and quantum key distribution over hundreds of kilometres. Scaling the complexity requires architectures containing multiple photon sources, photon counters and a large number of indistinguishable single photons.

Optically driving the radiative Auger transition.

In a radiative Auger process, optical decay leaves other carriers in excited states, resulting in weak red-shifted satellite peaks in the emission spectrum. The appearance of radiative Auger in the emission directly leads to the question if the process can be inverted: simultaneous photon absorption and electronic demotion. However, excitation of the radiative Auger transition has not been shown, neither on atoms nor on solid-state quantum emitters.