Physical Review A

By deriving a general joint measurability condition for any pair of dichotomic observables in arbitrary finite dimension, the authors established an operational connection between joint measurability and positivity of quasiprobability in arbitrary finite dimension. The authors also extend the formulation to $n$ observables and propose a quantum-switch-inspired interferometric scheme enabling the experimental certification of measurement incompatibility.

The authors experimentally demonstrate an electric dipole moment exceeding 1 Debye in a long-lived excited state of dysprosium. Using microwave and optical Stark spectroscopy, they characterize a Stark-coupled opposite-parity doublet, establishing a route toward a doubly polar quantum gas of atoms.

The authors show that balancing shorter and longer routes through stochastic path selection can improve entanglement distribution in quantum repeater networks. An intermediate routing bias yields higher throughput than consistently favoring either short or long paths across a broad range of network conditions.

The authors theoretically demonstrate vortex photoelectron holography in strong-field tunneling ionization, in which the vortex photoelectron is generated via tunneling ionization of an atom in a state with a nonzero magnetic quantum number. They show that the phase of the elastic scattering amplitude for the vortex electron–atom interaction can be extracted from the hologram.

A trapped Bose–Einstein condensate is steered through fast, stable cycles by mapping its quantum dynamics onto an effective classical process, enabling systematic optimization of each stroke of the cycle. This approach yields robust quantum engines that operate efficiently in finite time.

The authors demonstrate how locking an on-chip frequency comb to a reference laser induces a mechanism that redistributes energy across the spectrum of comb lines. By tapping into this energy shift, they show how to boost weak high-frequency signals, offering a way to stabilize compact precision microcombs.

The author shows that two postulates commonly employed in derivations of the Born rule, additivity and noncontextuality, are not equivalent and thus cannot be unified into a single postulate. Furthermore, additivity is found to be crucial in several alternative derivations of the Born rule, and none of the proposed equivalent assumptions in these works can serve as a substitute for it.

The authors propose a new scheme for creating entanglement between the center-of-mass motions of two microspheres that does not require external optical or microwave cavities. By applying a strong, uniform magnetic field, spin waves dominate, and by applying oscillating gradient fields, translational displacements of the spheres change the magnon energies, yielding a coupling between magnons and translational degrees of freedom.

The authors propose a simple method to directly characterize classical stochastic noise causing qubit dephasing through repetitive Ramsey interferometry measurements (RIMs) on the qubit. They demonstrate that each RIM with a short evolution time and suitably chosen control pulses directly samples the noise field, and the $n$-point correlations of the RIM outcomes are proportional to the $n$-point correlation functions of the noise processes.

The authors reformulate the NP-hard problem of finding a quantum stabilizer code’s minimum distance into a Quadratic Unconstrained Binary Optimization (QUBO) framework compatible with classical, quantum, and hybrid solvers. Testing the approach with quantum annealing and hybrid optimization, they identify hardware connectivity and embedding as the main limitations of current implementations.

The authors examine the performance of a single dephasing qubit probing the cutoff frequency of Ohmic-family environments across varying temperatures and coupling strengths. They find that elevated temperatures accelerate decoherence to shorten the optimal measurement time, demonstrating that thermal noise can serve as a resource to improve sensing precision by nearly two orders of magnitude compared to zero-temperature conditions for certain weakly coupled environments.

The authors develop a theory of radio-frequency dimer-projection spectroscopy in a unitary Fermi gas and show that the frequency-resolved spectrum exhibits a narrow peak on top of a broad continuum. The narrow peak arises from the coherent projection of condensed Cooper pairs onto a final-state dimer.

The authors formulate Bose-Einstein condensation in the grand canonical ensemble using a phase-density representation where a well-defined phase coexists with macroscopic density fluctuations. They show that the squared average order parameter accounts for only a $\pi /4$ fraction of the condensate. The missing contribution comes from amplitude fluctuations. An interferometric measurement scheme is proposed to experimentally test this prediction.

The authors demonstrate a drag-induced skin effect in a Bose-Fermi mixture, where interactions transfer non-Hermitian skin localization from one particle species to another. The results reveal an interaction-mediated mechanism for generating correlated non-Hermitian dynamics in quantum mixtures.