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Multi-partite entanglement is essential not only to understand large quantum ensembles but also to build useful quantum technologies. Armstronget al. demonstrate multimode entanglement of up to eight modes using programmable virtual networks based on linear optics that can be switched in real time.

Cloning an unknown quantum state is challenging and the limit on the quality of clones is set by the no-cloning theorem. Here, the authors demonstrated the surpassing of such a limit using an effective quantum cloner based on a hybrid probabilistic-deterministic linear amplifier.

Light can cool and control the motion of nanoscale resonators to the point that they oscillate with only a single quantum of vibrational energy. Hosseini et al. now demonstrate a technique for optically cooling four mechanical modes of a nanowire that enables highly sensitive force measurements.

Entanglement is not the only type of quantum correlation. Quantum discord is a broader measure of such non-classical interactions. An experimental investigation now shows how quantum discord can be consumed to encode information, even in the absence of entanglement.

Emulation of noiseless linear amplification of quantum states of light is demonstrated by post-selection of measurement data obtained by heterodyne detection. Using this protocol, Einstein–Podolsky–Rosen entanglement is recovered after its degradation by transmission loss. This protocol is applicable to other quantum communication protocols, including teleportation and remote state preparation.

The emission of entangled photon pairs from layered materials is attractive for quantum applications, but its observation in monolayers has remained elusive. Here, the authors report co- and counter-propagating photon pair emission in the telecom range from monolayer GaSe and the observation of high-fidelity Bell states in the counterpropagating configuration.

Quasi-phase matching (QPM) is a well-known technique to improve the efficiency of frequency conversion processes in 3D nonlinear optical materials. Here, the authors report the implementation of nanoscale QPM in 2D 3R-stacked twisted MoS₂, showing enhanced second harmonic generation and spontaneous parametric down-conversion.

A heralded squeezing gate with near unit fidelity is demonstrated, even for modest ancillary squeezing. A heralding filter is implemented in the feed-forward operation. With 6 dB of ancillary squeezing, a fidelity of 0.985 is experimentally obtained.

Precise and arbitrary control of an optical field that preserves optical coherence is an important requisite for many proposed photonic technologies. Here, a coherent optical memory based on photon echoes induced through controlled reversible inhomogeneous broadening is presented. The scheme allows storage of multiple pulses of light which can be arbitrarily recalled, time-stretched or split.

The quantum mechanical concept of ‘steering’ refers to the feasibility of one system to nonlocally affect, or steer, another system’s states through local measurements. Multipartite steering is now demonstrated in a programmable optical network.

Continuous-variable quantum networks are easier to implement than discrete-variable ones, but suffer from a lower teleportation fidelity. Here, the authors demonstrate a CV teleportation protocol exploiting heralded noiseless amplification to increase the fidelity, at the expense of probabilistic operation.

Multi-parameter metrology requires collective measurements on more than one copy of the same quantum state. Now, an optimal scheme for the estimation of qubit rotations has been demonstrated on superconducting and trapped-ion platforms.

The potential of 2D materials for space applications has been surfaced recently, however a comprehensive assessment of their suitability is currently missing. Here, the authors investigate the radiation effects in Earth’s atmosphere on various devices based on 2D transition metal dichalcogenides and hexagonal boron nitride.

Using photons to disseminate encryption codes with complete security is one of the great successes of quantum information science. It has now been shown that long-distance cryptographic communication is just as effective when the scheme involves measuring the wave properties of light, rather than its particle properties.

Continuous-variable quantum key distribution (CV-QKD) enables secure communication using standard telecom hardware, but losses in fibres and free space severely limit its reach. Here, the authors present an adaptive software filtering protocol which triples key rates and achieves up to a 400-fold boost in satellite scenarios.

It has long been known that light can be slowed and stopped in an atomic medium using electromagnetically induced transparency. Researchers have now shown how an optical resonator can help a single photon induce its own transparency, which could have exciting applications in quantum information science.

Cavity optomechanics have allowed insight into the quantum groundstate of macroscopic systems, by efficiently decoupling them from environmental vibrations and noise. Here, a simplified vertical optical levitation system is presented in which three physical processes lead to complex dynamical behaviour.

Non-orthogonal quantum states cannot be perfectly distinguished - a fact of central importance in quantum mechanics, from both a fundamental and practical viewpoint. The authors introduce an approach to this problem, using entangled measurements to distinguish quantum states better than what is possible with direct measurements.