Search

This work shows how to connect a fibre to a single-photon source based on quantum dots in microcavities. The alignment relies on reflectivity measurements. The structure is stable from room to cryogenic temperature and over several cooling cycles.

A versatile cloud-accessible single-photon-based quantum computing machine is developed, which shows a six-photon sampling rate of 4 Hz over weeks. Heralded generation of a three-photon Greenberger–Horne–Zeilinger state—a key milestone toward measurement-based quantum computing—is implemented.

The recently observed rotation of a photon's polarization by interaction with a single solid state spin has potential implications in quantum computing. Here, Arnold et al. demonstrate enhanced spin–photon coupling and polarization rotation via a coupled quantum dot/micropillar cavity system.

An optical non-linearity at the single-photon level is reported with a semiconductor quantum dot–cavity device. The device performs as an efficient single-photon filter that strongly suppresses the multiphoton components of incident coherent pulses.

A three-partite cluster state made of one semiconductor spin and two indistinguishable photons is generated from an InGaAs quantum dot embedded in a pillar microcavity. The three-partite entanglement rate is 0.53 MHz at the output of the device.

Quantum information processing requires a system in which a single photon controls a single atom and vice versa. Here, the authors demonstrate such reciprocal operation and achieve coherent manipulation of a quantum dot by a few photons sent on an optical cavity.

Bright and tunable single-photon sources are essential for future quantum technologies. Here, the authors deterministically couple a quantum dot to a pillar structure that enables application of electric fields to provide a tunable single-photon source with a demonstrated extraction efficiency of 53%.

For quantum technologies to become widespread and scalable, bright sources of indistinguishable single photons are essential. Through deterministic positioning of quantum dots in pillar cavities, Gazzano et al.present a solid-state single-photon source with brightness as large as 0.65 photons per pulse.

A single photon with near-unity indistinguishability is generated from quantum dots in electrically controlled cavity structures. The cavity allows for efficient photon collection while application of an electrical bias cancels charge noise effects.

The careful optimization of all components of a quantum emitter single photon source yields over 50% end-to-end efficiency, a benchmark for optical quantum technologies.

Quantum information science requires a source of entangled photon pairs, but existing sources suffer from a low intrinsic efficiency or poor extraction efficiency. Collecting emitted photons from quantum dots can be improved by coupling the dots to an optical cavity, but this is not easy for entangled photon pairs. Now, a suitable optical cavity has been made in the form of a 'photonic' molecule — two identical, connecting microcavities that are deterministically coupled to the optically active modes of a pre-selected quantum dot.

Following excitation with a resonant laser, on-demand generation of non-classical light states in photon-number superpositions of zero-, one- and two-photon Fock states is demonstrated from a GaAs-based cavity containing InAs quantum dots.

A photon-number Bell state is generated from a quantum dot by controlling the light–matter entanglement during spontaneous emission. This excitation protocol can be scaled up by using N consecutive π-pulses to deliver multimode photonic entanglement.

Data show that the presence of women in quantum science is affected by several detriments, especially for higher positions. This Manifesto outlines the values and goals of Women for Quantum—a group of female physics professors working in AMO physics, quantum many-body physics and quantum information - to foster an inclusive scientific community.

This Review describes progress in the fabrication of semiconductor quantum-dot structures, which are approaching the ideal single-photon emitter, and highlights the remaining challenges.