PERSPECTIVE
The authors offer an overview of progress and a future perspective of large-scale optical quantum entanglement. They cover a broad range of topics from the basics of continuous-variable optical quantum entanglement and a multiplexing methodology for the generation of large-scale quantum entanglement to future approaches toward practical usages of large-scale optical quantum entanglement. The content includes both pedagogical content and the search for future directions beyond the current frontier.
Warit Asavanant and Akira Furusawa
Phys. Rev. A 109, 040101 (2024)
LETTER
The authors investigate the use of time-crystal phases for metrology, providing a concrete proposal as quantum sensors of AC fields. Their performance shows several useful advantages due to their long-range spatiotemporal ordering, overcoming the shot noise limit along with long interrogation times and robustness.
Fernando Iemini, Rosario Fazio, and Anna Sanpera
Phys. Rev. A 109, L050203 (2024)
LETTER
Counterintuitively, the authors show that critical metrology not only remains robust in the presence of finite temperature but can also benefit from it. Moreover, in certain cases, excited states exhibit significantly more non-classical behavior than ground states, further contributing to quantum-enhanced metrology.
Laurin Ostermann and Karol Gietka
Phys. Rev. A 109, L050601 (2024)
LETTER
The authors study First-Passage-Time distributions, and how they can be computed for stochastic measurement currents. They gain insights into signal-to-noise-ratio bounds and false positive reduction strategies, and charge-resolved master equations.
Michael J. Kewming, Anthony Kiely, Steve Campbell, and Gabriel T. Landi
Phys. Rev. A 109, L050202 (2024)
NEW ARTICLE
The authors exploit a connection between the theoretical renormalization group equation flow and the expansion dynamics of strongly interacting quantum gases. This analysis shows that there shall be an emergent conformal symmetry that restricts the dynamics and limits entropy production in one dimension, while it is absent in three-dimensions.
Jeff Maki and Fei Zhou
Phys. Rev. A 109, L051303 (2024)
LETTER
Strongly correlated quantum many-body systems from condensed matter and particle physics are very hard to study classically and variational quantum algorithms (VQAs) may be hampered by barren plateaus, where energy gradients decay exponentially in the system size. The authors prove that this critical problem can be resolved by employing VQAs based on suitable isometric tensor network states, establishing a new route for the investigation of strongly correlated quantum matter on NISQ devices.
Qiang Miao and Thomas Barthel
Phys. Rev. A 109, L050402 (2024)
LETTER
The authors propose a chiral odd Chern number lattice supersolid (CLSS) state realized through designing the specially spatial dependence of the effective Rydberg-dressed interaction in a single component Rydberg-dressed Fermi gas in an optical lattice. They show multiple number-tunable chiral Majorana fermions can be supported in CLSS, with potential applications in topological quantum computation.
Shuai Li et al.
Phys. Rev. A 109, L051302 (2024)
LETTER
The authors theoretically describe the stabilization of crystalline structures in interaction-driven Bose-Einstein condensates by analytically deriving a complex-valued Ginzburg-Landau equation for pattern formation. The resulting equation captures the competition between linear instability induced by the drive and nonlinear suppression induced by interactions and, in agreement with recent experiments, explains the emergence of square grid density patterns as stable states.
Keisuke Fujii et al.
Phys. Rev. A 109, L051301 (2024)
LETTER
In the context of cavity optomechanics in the strong-coupling regime, the authors present a method for generating nonclassical motional states of a mechanical resonator. The states’ nonclassical nature, which is manifested by a strongly negative Wigner function, is found to be due to the interplay between the intrinsically nonlinear optomechanical interaction and the laser drive applied to the cavity.
Jonathan L. Wise, Clément Dutreix, and Fabio Pistolesi
Phys. Rev. A 109, L051501 (2024)
EDITORS' SUGGESTION
In an open system, environment-induced synchronization can occur between the expectation values of spin observables of a pair of qubits. Here, the authors apply a machine learning method to predict the emergence of such synchronization.
F. Mahlow et al.
Phys. Rev. A 109, 052411 (2024)
EDITORS' SUGGESTION
Boson sampling is a promising candidate for showcasing quantum advantage. However, achieving this advantage involves pinpointing the optimal balance between shallow-depth circuits, which are susceptible to classical simulation, and larger-depth circuits prone to noise. Here, the authors introduce a linear-optical circuit design with nonlocal gates, aimed at enhancing the probability of demonstrating advantage even with shallow circuit depths.
Byeongseon Go, Changhun Oh, Liang Jiang, and Hyunseok Jeong
Phys. Rev. A 109, 052613 (2024)
LETTER
The authors investigate whether nonequilibrium environments can promote localization rather than destabilize it. By studying the impact of quantum jumps on the localization transition in driven-dissipative systems, the authors reveal pathways to enhance localized regimes using simple yet realistic postselection schemes.
Sparsh Gupta, Hari Kumar Yadalam, Manas Kulkarni, and Camille Aron
Phys. Rev. A 109, L050201 (2024)