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Ramsey interferometry is widely used in quantum sensing for precise qubit frequency measurements, but its sensitivity is limited by decoherence. Hecht et al. report a new protocol for detecting qubit frequency shifts in a decohering system which has enhanced sensitivity and is applicable to existing technologies.

One of the ways excited-state atoms relax to ground state is by emitting radiation. Here the authors demonstrate sub- and super-radiant emission threshold from a cavity-mediated atomic ensemble of Sr atoms.

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.

Physicist behind precision spectroscopy and atomic clocks.

Studying long-range interactions in the controlled environment of trapped ultracold gases can help our understanding of fundamental many-body physics. Here the authors excite a gas of Rydberg atoms with a ps laser pulse, demonstrating behaviour consistent with many-body correlations beyond mean-field.

Impurity spins in silicon can be controlled with microwaves and then read-out electrically, offering a promising platform for quantum information applications. Here, the authors show that terahertz pulses can be used to address the orbital degree of freedom as well, which can also be detected electrically.

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.

NbN/AlN/NbN qubits prepared by atomic layer deposition allow for precise control of the tunnelling barrier and stable operation beyond the temperature limit of aluminium-based devices.

Compact atomic clocks and atom interferometers are desired for on-chip integration. Here the authors demonstrate a chip-scale atomic beam of 87Rb atoms and its application as an atomic beam clock

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.

Spin–photon interfaces provide a connection between quantum information stored in atomic or electronic spins and optical communications networks. A quantum photon emitter with long-lived, controllable coherent spin has now been demonstrated.

A tweezer clock containing about 150 ⁸⁸Sr atoms achieves trapping and optical excited-state lifetimes exceeding 40 seconds, and shows relative fractional frequency stability similar to that of leading atomic clocks.

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.

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.

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.

The sensitivity of single spins to their local environment makes them promising components for future quantum information and sensing technology. Here, the authors use geometric spin echo to demonstrate the control of nitrogen-vacancies via the crystal field in diamond under zero applied fields.

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.

Superconducting constrictions are an alternative source of nonlinearity to Al-based Josephson junctions, enabling new functionalities for qubits. Here, the authors demonstrate a high-frequency superconducting qubit in a single TiN thin film, based on coherent quantum phase slip tunneling through a constriction.

An 11-qubit atom processor comprising two precision-placed nuclear spin registers of phosphorus in silicon is shown to achieve state-of-the-art Bell-state fidelities of up to 99.5%.

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.

Nuclear spin-free materials like ²⁸Si show promising electron spin coherence times, but qubit operation still suffers from low-frequency noise. Here the authors address this by applying open- and closed-loop feedback control methods including real-time Hamiltonian parameter estimation and dynamic voltage pulsing.

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.

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.

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.

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.

Precise measurements of quantum scattering phase shifts have not been possible because the number of scattered atoms depends on phase shifts as well as the atomic density, which cannot be measured precisely. An alternative type of scattering experiment circumvents this problem, using interferometric measurements to detect phase shifts in a density-independent manner.

Long-distance quantum communication relies on interfacing qubits with telecom-band photons. Here the authors implement a solid-state spin-qubit based on a hole confined in a semiconductor quantum dot emitting photons in the telecom C-band.

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.

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.

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.

The thousands of nuclear spins surrounding gallium arsenide quantum dots can interface with electron spin qubits and photons. With quantum engineering, this nuclear spin ensemble becomes a robust register for quantum information storage.

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.

Optical clocks with a record low zero-dead-time instability of 6 × 10^–17 at 1 second are demonstrated in two cold-ytterbium systems. The two systems are interrogated by a shared optical local oscillator to nearly eliminate the Dick effect.

Oceans provide essential ecosystem services to human society, yet the climate impacts on blue capital have long been ignored. Incorporating the latest works on ocean science and economics, researchers show that accounting for the potential damage would almost double the social cost of carbon estimation.

A family of multi-qubit Rydberg quantum gates is developed and used to generate Schrödinger cat states in an optical clock, allowing improvement in frequency measurement precision by taking advantage of entanglement.

Number-state superpositions of the harmonic motion of a trapped beryllium ion are used to measure the oscillation frequency with quantum-enhanced sensitivity, achieving a mode-frequency uncertainty of about 10⁻⁶.

Noise is a fundamental obstacle to the stability of atomic optical clocks. An experiment now realizes the design of a spin-squeezed clock that improves interrogation times and enables direct comparisons of performance between different clocks.

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.

Quantum annealers hold promise of outperforming classical computers in solving hard optimization problems, but one main challenge is understanding the role of noise in quantum annealing. Here, the authors characterize the relevant noise sources in a tunable flux qubit, a building block for quantum annealers, and provide a benchmark for future work on highly-coherent quantum annealers.

Quantum communication networks would greatly benefit from the possibility to have solid-state emitters being directly interfaced with telecom fibers, without the need for wavelength conversion. Here, the authors demonstrate coherent control of an InAs/InP quantum dot, as well as entanglement between its electron spin and the frequency of a telecom photon.

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.

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.