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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.

The complete DNA sequence of the yeast Saccharomyces cerevisiae chromosome IV has been determined. Apart from chromosome XII, which contains the 1–2 Mb rDNA cluster, chromosome IV is the longest S. cerevisiae chromosome. It was split into three parts, which were sequenced by a consortium from the European Community, the Sanger Centre, and groups from St Louis and Stanford in the United States. The sequence of 1,531,974 base pairs contains 796 predicted or known genes, 318 (39.9%) of which have been previously identified. Of the 478 new genes, 225 (28.3%) are homologous to previously identified genes and 253 (32%) have unknown functions or correspond to spurious open reading frames (ORFs). On average there is one gene approximately every two kilobases. Superimposed on alternating regional variations in G+C composition, there is a large central domain with a lower G+C content that contains all the yeast transposon (Ty) elements and most of the tRNA genes. Chromosome IV shares with chromosomes II, V, XII, XIII and XV some long clustered duplications which partly explain its origin.

A noiseless linear amplifier for quantum states of an optical field is demonstrated. The amplifier is also used to enhance entanglement through a technique known as distillation. Such amplification and distillation may be useful for quantum cloning, metrology and communications.

Safely opening university campuses has been a major challenge during the COVID-19 pandemic. Here, the authors describe a program of public health measures employed at a university in the United States which, combined with other non-pharmaceutical interventions, allowed the university to stay open in fall 2020 with limited evidence of transmission.

Quantum channel correction could provide a remedy to unavoidable losses in long-distance quantum communication, but the break-even point has escaped demonstration so far. Here, the authors fill this gap using distillation by heralded amplification, followed by teleportation of entanglement.

Here we report the sequence of 569,202 base pairs of Saccharomyces cerevisiae chromosome V. Analysis of the sequence revealed a centromere, two telomeres and 271 open reading frames (ORFs) plus 13 tRNAs and four small nuclear RNAs. There are two Ty1 transposable elements, each of which contains an ORF (included in the count of 271). Of the ORFs, 78 (29%) are new, 81 (30%) have potential homologues in the public databases, and 112 (41%) are previously characterized yeast genes.

Quantum devices should allow simulating stochastic processes using less memory than classical counterparts, but only if quantum coherence is maintained through multiple steps. Here, the authors demonstrate a coherence-preserving three-step stochastic simulation using photons.

Measurements of an unknown optical phase have not yet been performed with the ultimate precision, i.e. saturating the Heisenberg limit. Here, Daryanoosh et al. demonstrate this with a precision within 4% of the Heisenberg limit by combining photonic entanglement and multiple passes.

Long-distance quantum communication is limited by optical absorption and scattering. A noiseless amplifier for photonic qubits coherently encoded across two optical modes is now demonstrated, which could combat this negative effect. The method enabled a fivefold increase in the transmission fidelity of the polarization state of a single photon.

Entangled photon states, obtained by post selection, are used to perform interferometric phase measurement with a sensitivity beyond the shot-noise limit.

Unconditional entanglement-enhanced photonic interferometry is implemented by using a state-of-the-art photon source and detectors. Sampling a birefringent phase shift, precision beyond the shot-noise limit is demonstrated without data correction.

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.

A manufacturable platform for quantum computing with photons is introduced and a set of monolithically integrated silicon-photonics-based modules is benchmarked, demonstrating dual-rail photonic qubits with performance close to thresholds required for operation.

Guaranteed entanglement sharing over long distances can be verified by violating a Bell inequality. That's a tricky enough proposition in itself, but what if more than two parties are involved?

Light is an excellent tool for making precise measurements of objects, but can sometimes alter or damage a sensitive sample. Researchers have now shown that entanglement and quantum-correlated light can be used to help alleviate this problem.

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.

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).

Polarization is a convenient way to encode quantum information for cryptography, remote transfer and optical quantum computing, but sharing entanglement is problematic over a noisy link. Hiding in an isolated corner of the state space can make a big difference.

Quantum systems are uncertain by nature. By 'squeezing' this uncertainty, physicists can make better measurements of quantities such as distance. But overdoing it makes things burst out all over the place.

At the fundamental level, measurement precision is limited by the number of quantum resources that are used. Standard measurement schemes lead to a phase uncertainty that scales with this number. In principle, it should be possible to achieve a precision limited only by the Heisenberg uncertainty principle. Here, an approach using unentangled single-photon states enables the achievement of Heisenberg-limited phase estimation. This represents a drastic reduction in the complexity of achieving quantum-enhanced measurement precision.

A general approach to simplifying quantum logic circuits—the ‘programs’ of quantum computers—is described and demonstrated on a platform based on photonic qubits.

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.

Chemogenomic screening is increasingly being applied to expedite the conversion of phenotypic screening projects into target-based drug discovery approaches. Here, Jones and Bunnage discuss the principles of the creation and use of chemogenomic libraries, highlighting key examples and their applications, including target identification, drug repositioning and predictive toxicology.