Single photons and quantum effects articles from across Nature Portfolio

Single spin defects are identified in gallium nitride at room temperature, exhibiting a spin readout contrast of up to 30%.

An efficient way of realising a large number of telecom single-photon emitters for quantum communication is still missing. Here, the authors use a wide-field imaging technique for fast localization of single InAs/InP quantum dots, which are then integrated into circular Bragg grating cavities featuring high single-photon purity and indistinguishability.

We report the NOON-state interference in the frequency domain. Two photons with distinct colors, blue and red, are injected into an interferometer constructed with two frequency beam splitters. The resultant interference pattern is then observed.

Interlayer excitons in 2D homo- and heterostructures have been intensively investigated due to their emerging optical properties. Here, the authors report the observation of interface excitons in 1D/2D carbon nanotube/WSe2 heterostructures, showing evidence of photon antibunching at room temperature.

Entangled local states can be made capable of violating Bell inequalities via nonlocality activation. Typical theoretical approaches require processing many copies of the original state and performing joint measurements on the ensemble. Here, instead, the authors experimentally demonstrate how to do so using a single copy of the state, broadcasting it to two spatially separated parties within a three-node network.

Single spin defects are identified in gallium nitride at room temperature, exhibiting a spin readout contrast of up to 30%.

Even by shining classical light on a single opening, one can perform a double-slit experiment and discover a surprising variety of quantum mechanical multi-photon correlations — thanks to surface plasmon polaritons and photon-number-resolving detectors.

A coherent microwave-to-optical conversion scheme, previously feasible only under cryogenic environments, has now been expanded to ambient conditions by using Rydberg atoms.

A scheme for fast, comprehensive characterization of high-dimensional quantum states could aid quantum applications in imaging and information processing.

The remarkable properties of graphene nanoribbons are promising for use in quantum technologies. To create quantum devices, however, individual nanoribbons must be contacted. This crucial step has now been demonstrated using single-walled carbon nanotubes as electrodes.

Contrary to intuition, photons do not have to be indistinguishable for maximum photon bunching to occur. Partially indistinguishable photons can exhibit pronounced bunching.