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A semiconductor quantum dot can passively mediate interactions between two photons, enabling the creation of entangled photon states.

An 11-qubit atom processor comprising two precision-placed nuclear spin registers of phosphorus in silicon is shown to achieve state-of-the-art Bell-state fidelities of up to 99.5%.

Entangled particles some distance apart can be used to show the strikingly nonlocal nature of quantum mechanics. Here the authors generate spatially separated pairs of helium atoms by colliding Bose-Einstein condensates and show that they are entangled by observing nonlocal correlations.

This study demonstrates the experimental realization of a complete protocol for quantum key distribution using entangled trapped strontium ions with device-independent quantum security guarantees.

Erwin Schrödinger introduced in 1935 the concept of ‘steering’, which generalizes the famed Einstein–Podolsky–Rosen paradox. Steering sits in between quantum entanglement and non-locality — that is, entanglement is necessary for steering, but steering can be achieved, as has now been demonstrated experimentally, with states that cannot violate a Bell inequality (and therefore non-locality).

A deterministic violation of the Bell inequality is reported between two superconducting circuits, providing a necessary test for establishing strong enough quantum entanglement to achieve secure quantum communications.

There are many quantum systems that act as high-quality quantum harmonic oscillators, and they can be used to store quantum information using the Gottesman–Kitaev–Preskill code. Entangling gates have now been demonstrated between two of these qubits.

A four-qubit processor of three phosphorus nuclear spins and an electron spin in silicon enables the implementation of a three-qubit Grover’s search algorithm with 95% fidelity. The implementation is based on an advanced multi-qubit gate with single-qubit gate fidelities above 99.9% and two-qubit gate fidelities above 99%.

Developing reliable resource characterization while guaranteeing resource efficiency is essential in practical quantum information processing. In this work, the authors show that the data obtained from entanglement distillation protocols can be further processed to efficiently and robustly characterize the entangled resources.

Practical implementations of quantum communication need to securely deliver information over long distances without line-of-sight. Towards this goal, Cuevas et al.use an actively stabilized interferometer to close the geometry loophole for a Bell inequality violation over 1 km of optical fibre.

Recent advancements have enabled quantum control and measurement of mechanical resonators. Here the authors demonstrate quantum entanglement between two mechanical resonators on separate substrates by sharing one and two quanta of energy, followed by quantum measurement of these entangled states.

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.

While Bell inequalities have been violated several times—mostly in photonic systems—their violations within particle physics experiments are less explored. Here, the BESIII Collaboration showcases Bell-violating nonlocal correlations between entangled hyperon pairs.

Quantum mechanics allows to generate nearly ideal random strings from initially weak random sources, important for security of data systems, but this remains elusive in practice. Here the authors propose a realistic, error-tolerant and secure protocol for randomness amplification of arbitrary bits.

While most quantum optical techniques reveal either the wave or particle nature of light, weak-field homodyne detection combines wave- and particle-like descriptions. Here, Donati et al.employ this hybrid detection scheme to study the coherence between photon number states across two-mode entangled states.

Quantum steering is a form of quantum non-locality that can be verified for arbitrarily low detection efficiencies and high losses at the price of requiring complete trust in one of the parties. Here, Kocsis et al. present measurement-device-independent steering protocols that remove this need for trust.

In this study, authors employ fragment-based lead discovery to identify WRN inhibitors. The fragment hits reveal an additional allosteric pocket and uncover a previously uncharacterized structural conformation of the WRN helicase domain with unique orientations of the ATPase domains

Untrustworthy sources or detectors mean that quantum entanglement cannot always be ensured, but quantum steering inequalities can verify its presence. Using a highly efficient system, Smithet al. are able to close the detection loophole and clearly demonstrate steering between two parties.

Researchers demonstrate a reconfigurable integrated quantum photonic circuit. The device comprises a two-qubit entangling gate, several Hadamard-like gates and eight variable phase shifters. The set-up is used to generate entangled states, violate a Bell-type inequality with a continuum of partially entangled states and demonstrate the generation of arbitrary one-qubit mixed states.

Wastewater-based surveillance tends to focus on specific pathogens. Here, the authors mapped the wastewater virome from 62 cities worldwide to identify over 2,500 viruses, revealing city-specific virome fingerprints and showing that wastewater metagenomics enables early detection of emerging viruses.

Baird et al. present the phase 2 PIONEER trial findings on the antitumor activity of combining aromatase inhibitor letrozole with megestrol in postmenopausal women with operable estrogen-receptor-positive human epidermal-growth-factor-receptor-2-negative breast cancer.

For a scenario of two separated but entangled observers, inequalities are derived from three fundamental assumptions. An experiment shows that these inequalities can be violated if quantum evolution is controllable on the scale of an observer.

Chemically induced protein degradation is a powerful alternative to classical inhibition, but some proteins have deeply masked binding pockets that make the development of degrader molecules difficult. Here, the authors discover an alternate site on nuclear receptors that can be targeted by degraders.

Piezoelectric coupling of a single superconducting qubit to two phononic crystal nanoresonators results in an integrated device that is able to control and read out the quantum state of the two mechanical resonators.

Here, the authors look at present day and medieval genome samples from Northern France to piece together demographic history and population structure across Brittany and the Loire basin.

Designing efficient and scalable specialized neuromorphic circuits to integrate raw nervous stimuli and respond identically to biological neurons remains a challenge. Here, the authors propose an analog programming strategy to emulate biological neurons in silico.

Entanglement of two nanophotonic quantum network nodes is demonstrated through 40  km spools of low-loss fibre and a 35-km long fibre loop deployed in the Boston area urban environment.

High-fidelity deterministic quantum state transfer and multi-qubit entanglement are demonstrated in a quantum network comprising two superconducting quantum nodes one metre apart, with each node including three interconnected qubits.

The approach to stabilizing a quantum state by coupling to engineered reservoirs is limited by a trade-off between state fidelity and stabilization rate. Here the authors implement a protocol based on parametric system-bath coupling to achieve fast and high-fidelity Bell state stabilization in a qutrit-qubit system.

A proof-of-principle study reports a complete photonic quantum computer architecture that can, once appropriate component performance is achieved, deliver a universal and fault-tolerant quantum computer.

Surgical sterilization alone cannot control global stray and feral domestic cat populations. Here, Godin et al. show that a single-dose injectable female sterilant administered before puberty safely and completely prevents pregnancy after maturity.

Tunable interactions in quantum many-body systems have practical applications in quantum technologies. The effective spin-dependent long-range interaction known as Rydberg dressing is now exploited to entangle a pair of ultracold neutral atoms.

Present day quantum technologies enable computations with tens and soon hundreds of qubits. A major outstanding challenge is to measure and benchmark the complete quantum state, a task that grows exponentially with the system size. Generative models based on restricted Boltzmann machines and recurrent neural networks can be employed to solve this quantum tomography problem in a scalable manner.

The BIG Bell Test, which used an online video game with 100,000 participants worldwide to provide random bits to 13 quantum physics experiments, contradicts the Einstein–Podolsky–Rosen worldview of local realism.