Search

In 1845, Faraday noted that the plane of polarization of light is rotated when a light beam travels through a material in a magnetic field. Now, Faraday rotation due to one single electron spin has been observed.

Spins confined to quantum dots are a possible qubit, but the mechanism that limits their coherence is unclear. Here, the authors use an all-optical Hahn-echo technique to determine the intrinsic coherence time of such spins set by its interaction with the inhomogeneously strained nuclear bath.

Quantum emitters have been recently isolated in 2D materials, yet their spatial controllability remains an open challenge. Here, the authors devise a method to create arrays of quantum emitters in WSe₂ and WS₂, by taking advantage of the strain distribution induced by a nanopatterned silica substrate.

Atomically thin transition metal dichalcogenides hold promise as scalable single-photon sources. Here, the authors demonstrate all-electrical, single-photon generation in tungsten disulphide and diselenide, achieving charge injection into the layers, containing quantum emitters.

Multi-exciton states may emerge in atomically thin transition metal dichalcogenides as a result of strong many-body interactions. Here, the authors report experimental evidence of four- and five-particle biexciton complexes in monolayer WSe₂ and their electrical control.

A quantum two-level system can be coherently excited by a phase-locked dichromatic electromagnetic field. This technique can make single-photon generation more efficient as the pump light does not overlap in frequency with the emitted single photons.

Defects in materials can be used to detect magnetic fields at the nanoscale. Here the authors show that a carbon-related defect in hexagonal boron nitride acts as a robust nanoscale sensor capable of vectorial magnetic field detection.

Group-IV color centers in diamond show promise for spin-photon interfaces, but precise positioning and activation are challenging. Here the authors combine site-controlled ion implantation with laser annealing and in-situ photoluminescence monitoring to create and tune individual tin vacancy centers in diamond.

A series of experiments that provide confirmation of the quantum nature of the quantum–dot–cavity system in the strong coupling regime by studying a photonic crystal nanocavity in which one, and only one, quantum dot is located precisely at the cavity electric field maximum.

The photoluminescent properties of electron spins at nitrogen–vacancy (NV) centres are promising for use in quantum information and magnetometry. It is now shown that the coherence times of NV centres in nanodiamonds can be engineered to be comparable to those of bulk diamond.

By implanting ¹¹⁷Sn, a fibre-packaged nanophotonic diamond waveguide with optically addressable hyperfine transitions separated by 452 MHz is demonstrated. This enables the formation of a spin-gated optical switch and achieving a waveguide-to-fibre extraction efficiency of 57%.

Quantum coherent control of single-photon-emitting defect spins have been reported in hexagonal boron nitride, revealing that spin coherence is mainly governed by coupling to a few proximal nuclei and can be prolonged by decoupling protocols.

The interaction of a quantum system with its surroundings is usually detrimental, introducing decoherence. Experiments now show how such interactions can be harnessed to provide all-optical control of the spin state of a quantum dot.

A promising approach to realizing a practical quantum bit scheme is the optical control of single electron spins in quantum dots. The reliable preparation and manipulation of the quantum states of such spins have been demonstrated recently. The final challenge is to carry out single-shot measurements of the electron spin without interfering with it. A technique has now been developed that enables such measurement, by coupling one quantum dot to another to produce a quantum dot molecule.

A single excitation in a semiconductor nuclear spin ensemble is detected with parts-per-million accuracy using the coupling between the ensemble and an electron-spin quantum dot.

Atoms in a semiconductor can have non-zero nuclear spins, creating a large ensemble with many quantum degrees of freedom. An electron spin coupled to the nuclei of a semiconductor quantum dot can witness the creation of entanglement within the ensemble.

Excitons are quasiparticles consisting of an electron-hole pair and can be used to study many-body phenomenon. Here, the authors demonstrate on-demand quantum confinement of long-lived interlayer excitons in WS₂/WSe₂ heterostructures deposited on nanopatterned substrates.