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Many features of a superconductor are encoded in the Josephson effect and understanding changes at the local level can help explain related phenomena. Here, the authors use scanning tunnelling microscopy to study local changes in the Josephson effect and how they relate to the transport channel configuration.

A materials platform using tantalum as a base layer and silicon as the substrate to construct superconducting qubits enables device performance improvements such as millisecond lifetimes and coherence times, as well as high time-averaged quality factors.

The long-predicted suppression of quasiparticle dissipation in a Josephson junction when the phase difference across the junction is π is inferred from a sharp maximum in the energy relaxation time of a superconducting artificial atom.

The beamsplitter operation is a key component for quantum information processing, but implementations in superconducting circuit-QED usually introduce additional decoherence. Here, the authors exploit the symmetry within a SQUID, driven in a purely differential manner, to realise clean BS operations between two SC cavity modes.

The emergence of a giant phonon anomaly in the pseudogap phase of underdoped cuprate superconductors has been assumed to be a consequence of instability towards a charge density wave state. Here, the authors present a theory suggesting the anomaly arises due to large superconducting fluctuations.

Understanding loss mechanisms in superconducting circuits is crucial for improving qubit coherence. Here the authors use a multimode resonator to study loss mechanisms in thin-film superconducting circuits and demonstrate on-chip quantum memories with lifetimes exceeding 1ms, using Ta thin-films and high-temperature substrate annealing

The ability to transfer quantum information from a memory to a flying qubit is important for building quantum networks. The very fast release of a multiphoton state in a microwave cavity memory into propagating modes is demonstrated.

An artificial Kerr medium has been engineered using superconducting circuits, enabling the observation of the characteristic collapse and revival of a coherent state; this behaviour could, for example, be used in single-photon generation and quantum logic operations.

Wireless communication, non-destructive testing and material identification propel the development of the Terahertz frequency region. Here the authors present a fast tunable measurement system with a frequency coverage of 6.5 THz suitable for metrological applications.

Quantum computers based on superconducting transmon qubits are limited by single qubit lifetimes and coherence times, which are orders of magnitude shorter than limits imposed by bulk material properties. Here, the authors fabricate two-dimensional transmon qubits with both lifetimes and coherence times longer than 0.3 milliseconds by replacing niobium with tantalum in the device.

One of two papers that demonstrate the communication of individual quantum states between superconducting qubits via a quantum bus. This quantum bus is a resonant cavity formed by a superconducting transmission line of several millimetres. Quantum information, initially defined in one qubit on one end, can be stored in this quantum bus and at a later time retrieved by a second qubit at the other end.

Bosonic systems live in an infinite-dimensional space, and in order to be able to describe them one usually reduces it to an effective finite dimension or constrain the dynamics in some way, but it is not fully understood whether this captures all the physics at play. Here, the authors fill this gap showing that such representations can successfully and rigorously approximate bosonic physics.

Synchronization of nanoscale photonic devices generating pulses is of prime importance for on-chip communications and analog all-optical machines. Beyond synchronization, by using non-identical thermo-optical self-pulsing photonic crystal integrated on silicon circuit, the authors demonstrate multiple complex behaviors of the temporal dynamics in the parameter space.

A hybrid superconducting optoelectronic circuit could be used to develop spiking neuromorphic networks that operate at the single-quantum level.

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.

Quantum computing platforms allowing quantum error correction usually rely on complex redundant encoding within multiple two-level systems. Here, instead, the authors realize a CNOT gate between two qubits encoded in the multiphoton states of two microwave cavities nonlinearly coupled by a transmon.

Interaction between Cooper pairs and other collective excitations may reveal important information about the pairing mechanism. Here, the authors observe a universal jump in the phase of the driven Higgs oscillations in cuprate thin films, indicating the presence of a coupled collective mode, as well as a nonvanishing Higgs-like response at high temperatures, suggesting a potential nonzero pairing amplitude above Tc.

Magnetic impurities on superconductors lead to bound states within the superconducting gap, so called Yu-Shiba-Rusinov (YSR) states. Here, the authors study tunneling from a vanadium STM tip to a V(100) surface and show that YSR states can be excited at very low temperature by applying a microwave signal.

Measurements of the superfluid stiffness in twisted trilayer graphene reveal unconventional nodal-gap superconductivity, where the superconducting transition is controlled by phase fluctuations rather than Cooper-pair breaking.

Fault-tolerant manipulation of quantum bits is demonstrated experimentally on an eight-photon cluster state using topological error correction.

Cuprate superconductors are known for their intertwined interactions and coexistence of competing orders. Here, the authors observe a Fano resonance in the nonlinear THz response of La_2-xSr_xCuO₄, which may arise from a coupling between superconducting and charge-density-wave amplitude fluctuations.

Two superconducting cavity modes are entangled using an exponential-SWAP logic gate.

Transistors have continuously reduced in size and increased in switching speed since their invention in 1947. The exponential pace of transistor evolution has led to a revolution in information acquisition, processing and communication technologies. And reigning over most digital applications is a single device structure — the field-effect transistor (FET). But as device dimensions approach the nanometre scale, quantum effects become increasingly important for device operation, and conceptually new transistor structures may need to be adopted. A notable example of such a structure is the single-electron transistor, or SET^1,2,3,4. Although it is unlikely that SETs will replace FETs in conventional electronics, they should prove useful in ultra-low-noise analog applications. Moreover, because it is not affected by the same technological limitations as the FET, the SET can approach closely the quantum limit of sensitivity. It might also be a useful read-out device for a solid-state quantum computer.

Interactions between light and an ensemble of strontium atoms in an optical cavity can serve as a testbed for studying dynamical phase transitions, which are currently not well understood.

It was previously thought that the nerves in the pectoral fin of fish came solely from the spinal cord. Here, motoneurons in ray-finned fish are shown to also originate from the hindbrain, demonstrating that innervation was from both the hindbrain and the spinal cord in ancesteral vertebrates.

Photon Bose–Einstein condensation is observed in a semiconductor laser, where thermalization and condensation of photons occur using an InGaAs quantum well and an open microcavity. The distinction between regimes of photon Bose–Einstein condensation and conventional lasing are clearly identified.

Dual-rail encodings of quantum information can be used to detect loss errors, allowing these errors to be treated as erasures. The measurement of dual-rail states with error detection has now been demonstrated in superconducting cavities.

Circuit quantum acoustodynamics is used to achieve controlled generation of multi-phonon Fock states in a bulk acoustic-wave resonator, which are demonstrated to have a quantum nature.

Placing a single layer of tungsten diselenide in contact with twisted bilayer graphene enables superconductivity even for non-magic twist angles where insulating behavior is absent.

Thermoelectric measurements show an unusual form of critical behaviour at the superconducting quantum phase transition in monolayer WTe₂.

Readout of a superconducting qubit embedded in a circuit quantum electrodynamics architecture is demonstrated at optical frequencies through a low-noise electro-optomechanical transducer.

Two below-threshold surface code memories on superconducting processors markedly reduce logical error rates, achieving high efficiency and real-time decoding, indicating potential for practical large-scale fault-tolerant quantum algorithms.

The flux of autophagosomes in the heart tissue of mice can be imaged via the intravenous injection of iron oxide nanoparticles decorated with fluorescent peptides cleavable by lysosomal cathepsins.

The physics of Yu-Shiba-Rusinov states which exist in the superconducting gap are a topical area of research and linked to exotic phenomena such as Majorana fermions. Here, the authors use scanning tunnelling microscopy to investigate the influence of impurities on a superconducting surface and the role impurity-substrate hybridisation has on such states.

A quantum-error-correction system is demonstrated in which natural errors due to energy loss are suppressed by encoding a logical state as a superposition of Schrödinger-cat states, which results in the system reaching the ‘break-even’ point, at which the lifetime of a qubit exceeds the lifetime of the constituents of the system.

The quantized changes in the photon number parity of a microwave cavity can be tracked on a short enough timescale, and with sufficiently little interference with the quantum state, for this parity observable to be used to monitor the occurrence of error in a recently proposed protected quantum memory.