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Breaking of Lorentz symmetry is related to the unification of fundamental forces and the extension of the standard model. Here the authors provide updated bounds on the Lorentz violation, by using measurements with trapped Yb+ ion, that represent an improvement over existing results.

Frequency combs provide a broad series of well-calibrated spectral lines for highly precise metrology and spectroscopy, but this usually involves a trade-off between power and accuracy. A comb created by adjusting the time delay between two optical pulses now enables both. This so-called Ramsey comb could probe fundamental problems such as determining the size of the proton.

Reducing rotational dephasing is a major challenge in ultracold molecules. Here, the authors demonstrate coherent control of three rotational states in ultracold molecules trapped in magic-wavelength optical tweezers, opening prospects towards quantum applications with higher-dimensional systems.

Ionizing radiation can cause simultaneous charge noise in multi-qubit superconducting devices. Here, the authors measure space- and time-correlated charge jumps in a four-qubit system in a low-radiation underground facility, achieving operation with minimal correlated events over 22 h at qubit separations beyond 3 mm.

Coherence between rotational states of polar molecules has previously been limited by light shifts in optical traps. A magic-wavelength trap is able to maximize the coherence time and enables the observation of tunable dipolar interactions.

Tunable itinerant spin dynamics enabled by dipolar interactions are demonstrated with polar molecules, establishing an interacting spin platform that allows for exploration of many-body spin dynamics and spin-motion physics using strong, tunable dipolar interaction.

Decoherence is anathema to quantum systems, as it reduces their performance and stability. Shulman et al.show that real-time Hamiltonian parameter estimation can significantly increase the coherence time of a qubit by enabling continuous adjustment of its control parameters.

The hyperfine states of ultracold polar molecules are a strong candidate for storing quantum information. Identifying and eliminating all detectable causes of decoherence has extended the qubit coherence time beyond 5.6 s in RbCs molecules.

Atomic defects in semiconductors, like nitrogen-vacancy centres in diamond, are promising as solid state systems for quantum computing. Here, the authors show the complete quantum control of an exciton qubit formed from an isoelectronic centre in GaAs, establishing this material as a promising alternative.

Using spin-5/2 nuclei of ¹⁷³Yb atoms trapped in an optical lattice, a Schrödinger-cat state persists for a coherence time of 1.4 × 10³ s. In measuring external magnetic fields, the cat state exhibits a sensitivity approaching the Heisenberg limit.

Ramsey interferometers are used to measure minute energy shifts, but they are usually only applied to simple, non-interacting ensembles. Here, the authors demonstrate a two-pulse Ramsey-type interferometer built on the motional states of an interacting Bose–Einstein condensate using optimal control.

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.

Researchers demonstrate fast, single-qubit gates using a sequence of 13 ps pulses. Two vertically stacked InAs/GaAs quantum dots were coupled through coherent tunnelling and charged with controlled numbers of holes. The interaction between hole spins was investigated by Ramsey fringe experiments, showing a tunable interaction range of tens of gigahertz.

Solid-state systems are established candidates to study models of many-body physics but have limited control and readout capabilities. Ensembles of defects in diamond may provide a solution for studying dipolar systems.

Many-body effects in an interacting spin-orbit coupled Fermi gas are studied with the help of clock spectroscopy. The results provide a simple view of how strong collective dynamics arise from local interactions in the presence of spin–orbit coupling.

Using a long-lived quantum-dot spin qubit coupled to a GaAs-based photonic crystal cavity, researchers demonstrate complete quantum control of an electron spin qubit. By cleverly controlling the charge state of the InAs quantum dot using laser pulses, optical initialization, control and readout of an electron spin are achieved.

Hole spin qubits in germanium have seen significant advancements, though improving control and noise resilience remains a key challenge. Here, the authors realize a dressed singlet-triplet qubit in germanium, achieving frequency-modulated high-fidelity control and a tenfold increase in coherence time.

Silicon is a promising material for realization of quantum processors, particularly as it could be naturally integrated with classical control hardware based on CMOS technology. Here the authors report a silicon qubit device made with an industry-standard fabrication process on a CMOS platform.

Cold-atom interferometers have been miniaturized towards fieldable quantum inertial sensing applications. Here the authors demonstrate a compact cold-atom interferometer using microfabricated gratings and discuss the possible use of photonic integrated circuits for laser systems.

The authors fabricate a fluxonium circuit using a granular aluminium nanoconstriction to replace the conventional superconductor–insulator–superconductor tunnel junction. Their characterization suggests that this approach will be a useful element in the superconducting qubit toolkit.

Trapped ion quantum systems based on sympathetic cooling use ions of different species. Here the authors demonstrate exchange cooling using two ions of the same species (⁴⁰Ca⁺) by taking advantage of the exchange of energy when the ions are brought close together.

Interspecies comparisons between atomic optical clocks are important for several technological applications. A recently proposed spectroscopy technique extends the interrogation times of clocks, leading to highly stable comparison between species.

Cosmic-ray particles and γ-rays striking superconducting circuits can generate qubit errors that are spatially correlated across several millimetres, hampering current error-correction approaches.

Two-qubit operations exceeding 99% fidelity have been demonstrated by silicon devices made with standard semiconductor tooling in a 300-mm foundry environment.

Optical control over electron spins embedded in semiconductor structures is an efficient way of manipulating quantum information. But a fully fledged quantum information processor will require control over two-spin states. This has now been demonstrated, including the implementation of ‘ultrafast’ two-qubit gate operations that take less than a nanosecond.

Superconducting qubits are highly sensitive to magnetic fields, limiting their integration with spin-based quantum systems. Here, the authors demonstrate a superconducting qubit that maintains coherence beyond 1T, revealing spin-1/2 impurities and magnetic freezing of flux noise.

Quantum sensing based on solid-state spins can be improved with the use of adaptive strategies.

Here the authors use Ramsey interferometry to study Tan’s contact in uniform two-dimensional Bose gas of 87Rb atoms across the Berezinskii–Kosterlitz–Thouless superfluid transition. They find that the two-body contact is continuous across the critical point.

By engineering an exceptionally controlled environment using rotationally magic optical tweezers, long-lived entanglement between pairs of molecules using detectable hertz-scale interactions can be achieved.

In large qubit registers, long coherence times and individual qubit control are difficult to achieve at the same time. Here, the authors assemble a 2D register of qubits in an array of fermionic alkaline-earth atoms, where tailored pulses can be applied to subsets of individual qubits in parallel.

Experiments demonstrate the powerful capabilities of ultracold molecules to study dynamics in the context of quantum magnetism, and create new possibilities for studying quantum physics with ultracold molecules more broadly.

A possible route to scalability of trapped-ion-based quantum computing platforms is to connect multiple modules where ions can be shuttled across different registers. Here, the authors demonstrate fast and low-loss transfer of trapped ions between two microchip modules.

The authors report an experiment demonstrating fast control of the quantum dot–cavity coupling, indicating the coherent transfer of photons between the cavity and the quantum dot.

Quantum error correction plays a key role in quantum information and metrology, but generally requires complex gates and measurements sequences. Here, the authors use trapped ions to implement a scheme in which always-on coupling to an engineered environment protects the qubit against errors.

High-dimensional quantum bits advance the application of quantum sensing and information processing technologies but suffer from the low spectral selectivity and working temperature. Here the authors present the selective excitation and control of spin qudits modes based on an ensemble of silicon vacancy defects in silicon carbide at room temperature.

While a quantum system is always disturbed by any observation, one can exploit the back action of measurements and strong couplings to tailor the system evolution via quantum Zeno dynamics. Schäfer et al. demonstrate quantum Zeno dynamics in a five-level Hilbert space using a ⁸⁷Rb Bose–Einstein condensate.

Errors in a quantum computer that are correlated between different qubits pose a considerable challenge for correction schemes. Measurements of noise in silicon spin qubits show that electric field fluctuations can create strongly correlated errors.

Gatemons, or gate-tunable transmons, are superconducting qubits based on hybrid Josephson junctions, which typically use extended quantum conductors as weak links. Here the authors report a gatemon made with a carbon-nanotube-based junction, showing improved coherence time compared to graphene-based devices.

Repeated error correction creates a logical qubit encoded in the hybrid state of a superconducting circuit and a bosonic cavity, which is shown to be fully controllable under a universal single-qubit gate set.

Using an artificial three-level lambda system realized in a superconducting transmon qubit in a microwave cavity one can observe coherent population trapping, electromagnetically induced transparency and superluminal pulse propagation.

Quantum dot spin qubits in Si can be controlled using micromagnet-based electric-dipole spin resonance, but experiments have been limited to small 1D arrays. Here the authors address qubit control in 2D Si arrays, demonstrating low-frequency control of qubits in a 2 x 2 array using hopping gates.

Nuclear spins in solid-state systems can have very long coherence times, which makes them attractive for use as qubits. Now a nuclear spin qubit device has been developed with all-microwave two-qubit control that has important performance benefits.

Superconducting qubits are measured using microwaves, posing constraints on its size and thermal budgets. The electro-optic transceiver presented here can be used to perform optical readout without affecting qubit performance.

An array of ⁸⁷Rb atoms with inter-atomic distances of 1.5 μm is prepared by holographic optical tweezers. When a pair of nearby ⁸⁷Rb atoms is optically excited to a Rydberg state, the energy exchange between the atoms is observed on a timescale of nanoseconds.

In a step towards developing a system in which to study quantum magnetism, the long-range dipolar interactions of polar molecules pinned in a three-dimensional optical lattice are used to realize a lattice spin model.

Open quantum systems are subject to dephasing that ultimately destroys the information they hold. Here, the authors use a superconducting qubit to show that dephasing also has a geometric origin, which can either reduce or restore coherence depending on the path of the quantum system in its Hilbert space.