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Exploring correlations in strongly entangled quantum materials is of interest. Here the authors generate a tunable spin-, trajectory-, and energy-entangled neutron beam using a neutron spin-echo interferometer and show violations of Clauser-Horne-Shimony-Holt and Mermin contextuality inequalities with micron-scale trajectory separation.

A loophole-free violation of Bell’s inequality with superconducting circuits shows that non-locality is a viable new resource in quantum information technology realized with superconducting circuits, promising many potential applications.

Qubit-cavity entanglement can be used for quantum information processing and for investigating the quantum-to-classical transition with high control. Here, the authors characterize the entanglement between an artificial atom and a cat state and its susceptibility to decoherence through Bell test witnesses.

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.

Entanglement between photons is easily destroyed by losses in optical systems as light propagates through it. For entanglement of orbital angular momentum, McLaren et al.show that losses caused by obstructions in the beam path can be overcome if measurements are made in the Bessel basis.

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.

The authors find the human red nucleus is functionally connected with action and motivated behavior networks, instead of motor-effector networks. They argue the red nucleus implements goal-directed behavior, integrating behavioral valence and action plans.

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.

The advantage of living in cities compared with rural areas with respect to height and BMI in children and adolescents has generally become smaller globally from 1990 to 2020, except in sub-Saharan Africa.

We demonstrate a programmable thin-film lithium niobate photonic circuit capable of high-brightness generation and reconfigurable projection of path-encoded Bell states with high fidelity.

The correlations exhibited by multipartite quantum systems composed of more than two entangled subsystems are more difficult to describe than those of bipartite quantum systems. Fritzet al.propose a principle of 'local orthogonality' as a key element to describing multipartite quantum correlations.

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.

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.

Radiation and conduction are generally considered as the main energy transport mechanisms for the evolution of early supernova remnants. Here the authors experimentally show the role of electron heat transfer on the growth of Rayleigh–Taylor instability in young supernova remnants.

A violation of Bell’s inequality would prove that a classical deterministic view of the universe is incorrect; however, despite long-standing efforts, irrefutable experimental proof of such a violation has yet to be produced. Teo et al. propose a realistic scenario that may finally overcome this challenge.

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.

A long-standing debate on the foundation of quantum mechanics is whether wave–particle duality and the uncertainty principle are equivalent. Here Coles et al. show that the wave–particle duality relation corresponds to a formulation of the uncertainty principle in terms of min- and max-entropies.

Scalable photonic devices for quantum information processing require on-chip quantum states engineering. Here the authors report the creation of entangled photon pairs on a silicon-on-insulator chip by integrating resonant photon sources, spectral demultiplexers and reconfigurable optics in a single device.

Continuous-variables EPR states present a resource for applications to quantum information processing and metrology, but these states have been created until now only with photon pairs. Here, the authors report the creation of an EPR-correlated two-mode squeezed states in an ultracold atomic ensemble.

Physical theories can be classified by the strength of the correlations that they allow to be generated between systems. Here, the authors introduce the set of almost quantum correlations that, despite being larger than strict quantum correlations, do not lead to operational contradictions.

Healthy adults were tracked before, during and after high doses of psilocybin and methylphenidate to assess how psychedelics can change human brain networks, and psilocybin was found to massively disrupt functional connectivity in cortex and subcortex with some changes persisting for weeks.

Genuine, unpredictable quantum random-number generation that is provably secure against quantum and classical adversaries is demonstrated, certified by the loophole-free violation of a Bell inequality.

Harnessing the entanglement of different ionic species could bring new flexibility in quantum computing, and now two groups independently demonstrate entanglement between different atomic species; Tan et al. achieve entanglement between different elements, whereas the related paper by Ballance et al. shows entanglement between different atomic isotopes, together demonstrating a first step towards mixed-species quantum logic.

Estimates from the Global Dietary Database indicated that 2.2 million new type 2 diabetes and 1.2 million new cardiovascular disease cases were attributable to sugar-sweetened beverages worldwide in 2020, with the highest burdens in sub-Saharan Africa, Latin America and the Caribbean.

Web summaryHarnessing the entanglement of different ionic species could bring new flexibility in quantum computing, and now two groups independently demonstrate entanglement between different atomic species; Ballance et al. achieve entanglement between different atomic isotopes, whereas the related paper by Tan et al. shows entanglement between different elements, together demonstrating a first step towards mixed-species quantum logic.

In general, it isn’t known when a quantum computer will have an advantage over a classical device. Now it’s proven that computers with limited working memory are more powerful if they are quantum.

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).

Bell inequalities are a quantitative measure that can distinguish classically determined correlations from stronger quantum correlations, and their measurement provides strong experimental evidence that quantum mechanics provides a complete description. The violation of a Bell inequality is now demonstrated in a solid-state system; the experiment provides further strong evidence that a macroscopic electrical circuit is really a quantum system.

An analysis based on data from the Global Dietary Database shows mean animal-sourced food intakes among children and adolescents increased modestly from 1990 to two portions per day in 2018, but remain low in sub-Saharan Africa, India and Bangladesh.

A Bell experiment that is ‘loophole’ free—leaving no room for explanations based on experimental imperfections—reveals a statistically significant conflict with local realism

Modeling analysis from the Global Dietary Database estimated that 70% of new global cases of type 2 diabetes are attributable to suboptimal intake of 11 dietary factors, with substantial differences in dietary risks across world regions and nations.

Entanglement is an important resource in quantum-enhanced technologies, but it is difficult to generate, especially in solid-state systems. An experiment now demonstrates the entanglement of two nuclear spins via a parity measurement of the electron spin in a nitrogen-vacancy centre in diamond.

Recent estimates of sugar-sweetened beverages (SSBs) intake are generally unavailable. Here the authors show a global SSBs intake of 2.7 servings/week in 2018 in adults (range: 0.7 South Asia, 7.8 Latin America/Caribbean); intakes were higher among males, younger, more educated, and urban adults.

Quantum entanglement is demonstrated in a system of massive micromechanical oscillators coupled to a microwave-frequency electromagnetic cavity by driving the devices into a steady state that is entangled.

Early environmental factors, like disadvantage, are associated with neurocognitive development. Here, the authors find that neonates and toddlers from economically disadvantaged backgrounds show accelerated brain development, with implications for language abilities in toddlerhood.

Dietary quality is reported at the global, regional and national level across 185 countries. Though diet quality increased modestly since 1990 at the global level, in South Asia and Sub-Saharan Africa it did not improve. In some regions, children’s dietary quality is lower than that of adults.

Functional MRI studies across ages show that the classic homunculus of the motor cortex in humans is in fact discontinuous, alternating with action control-linked regions termed the somato-cognitive action network.

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.

Quantum systems produce correlations that cannot be mimicked by classical resources, which can be used to certify quantum states without trusting the underlying devices. A network can perform this procedure for pure states with any number of systems.