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Qubit-based simulations of gauge theories are challenging as gauge fields require high-dimensional encoding. Now a quantum electrodynamics model has been demonstrated using trapped-ion qudits, which encode information in multiple states of ions.

A twin-field quantum key distribution protocol based on optical coherence is deployed over a 254-kilometre commercial telecom network, demonstrating that coherence-based quantum communication can be aligned with existing telecommunication infrastructure.

A transducer that generates microwave–optical photon pairs is demonstrated. This could provide an interface between optical communication networks and superconducting quantum devices that operate at microwave frequencies.

A lack of non-destructive measurements and difficulty in tuning direct coupling between motional modes limits quantum information processing with trapped ions. Both features have now been achieved in an ion crystal using oscillating electric fields.

The realization of the fractional quantum Hall effect with ultracold atoms in optical lattices is much sought after. Here, the authors propose a new way of obtaining fractional quantum Hall states in lattice systems by transforming a nonlocal abstract model into an implementable scheme.

Deterministic generation of photonic multi-partite entangled states has previously been achieved for specific states using ad-hoc devices. Here, the authors present a single superconducting circuit device to deterministically generate a variety of states, namely W, GHZ, and cluster states.

Networks have been widely explored in the context of classical statistical mechanics. But when quantum effects are added, qualitatively different behaviours emerge, even for the simplest cases.

Analogue quantum simulators have looser requirements than digital ones, but rigorous results on their usefulness in the noisy case are few. Here, the authors conclude that analogue quantum simulators are robust to errors and can provide superpolynomial to exponential quantum advantage when used to compute relevant many-body observables.

Perfect State Transfer is known to time-optimally connect distant nodes in a network. Here, the authors implement it on a chain of superconducting qubits and demonstrate that it also serves as a powerful tool for generating multi-qubit entanglement.

Linnerbauer and colleagues find that HB-EGF produced by reactive astrocytes is protective during autoimmune neuroinflammation, but epigenetically suppressed during late stages.

Most quantum technologies rely upon quantum wires to ensure the faithful transfer of quantum states between remote locations—a process that is especially vulnerable to decoherence. Yao et al.propose a means to harness topological protection to design a quantum wire that is intrinsically robust against decoherence.

An analogue quantum simulator based on ultracold atoms in optical lattices and cavity quantum electrodynamics is proposed for the solution of quantum chemistry problems and tested numerically for a simple molecule.

Applying the language of computational complexity to study real-world experiments requires a rigorous framework. Here, the authors provide such a framework and establish that there can be an exponential savings in resources if an experimentalist can entangle apparatuses with experimental samples.

Electron spins at nitrogen-vacancy centres in diamond are thought to be the most promising building blocks for practical realizations of quantum computers. Yaoet al. present a scalable architecture for a quantum information processor based on such vacancy centres that operates at room temperature.

Novel trapping mechanisms for ultracold atoms in specially engineered two-dimensional photonic crystals are proposed. The photonic crystal waveguides provide versatile means for creating strongly long-range atom–atom interactions mediated by photons.

In quantum information science, dissipation is commonly viewed as an adverse effect that destroys information through decoherence. But theoretical work shows that dissipation can be used to drive quantum systems to a desired state, and therefore might serve as a resource in quantum computations.

Tensor network states efficiently parametrize many-body quantum ground states and entanglement properties of strongly correlated systems. Here, the authors show how the presence of anyons and topological order can be related to symmetry breaking in the virtual boundary theory of the network.

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.

A potentially general mechanism for symmetry breaking in mesoscopic quantum systems is revealed in a theoretical study, which shows how, in a rotating Bose–Einstein condensate, the symmetry properties of the true many-body state are related to those of its mean-field approximation.

The observation of controlled adiabatic evolution from paramagnetic into ferromagnetic order in a system made of two trapped ions represents an initial step into the emerging field of quantum simulation.

Quantum mechanics has potential applications in communication and computation. But first a quantum connection — known as entanglement — has to be created between bigger and bigger objects.

Researchers propose that a cold atom in a one-dimensional photonic crystal waveguide can form a cavity. This system should allow interaction with other atoms within the effective cavity length.

The first generation of global-scale quantum networks are expected to make extensive use of satellite-mediated channels. As a first step towards this goal, this manuscript proposes a full-scale architecture to implement the exchange of quantum information, taking us from use cases through to a detailed plan for the road ahead.

Microwave stimulation of a superconducting artificial three-level atom is used to demonstrate high-fidelity, non-Abelian geometric transformations, the results of which depend on the order in which they are performed.

An experiment now demonstrates the deterministic continuous-variable teleportation between two atomic ensembles at room temperature. This protocol makes it possible to teleport time-evolving quantum states from one ensemble to the other.

The coherence of a close-to-ideal laser beam can be quadratically better than what was believed to be the quantum limit. This new Heisenberg limit could be attained with circuit quantum electrodynamics.

A type of stochastic neural network called a restricted Boltzmann machine has been widely used in artificial intelligence applications for decades. They are now finding new life in the simulation of complex wavefunctions in quantum many-body physics.