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 establish a connection between nonstabilizerness and a readily measurable property – the entanglement spectrum. This connection not only provides a deeper understanding of quantum complexity but also offers a practical way to probe nonstabilizerness even in noisy environments.
Emanuele Tirrito et al.
Phys. Rev. A 109, L040401 (2024)
LETTER
Many-body theory is used to study positron binding in halogenated hydrocarbons . As well as reproducing recent experimental binding energies, the general effect of halogenation is discussed and explained: fluorinated molecules generate a weaker positron-molecule correlation potential than their chlorinated and brominated counterparts owing to fluorinated molecules having higher molecular orbital ionization energies and a lower density of electron states near the highest occupied molecular orbitals.
J. P. Cassidy et al.
Phys. Rev. A 109, L040801 (2024)
LETTER
In a parity-time (PT) symmetric photonic dimer structure, the authors analytically obtained the phase diagram with quantum jumps induced by loss and gain, defined a Hermitian exchange operator to characterize different PT phases, and engineered the quantum state and Hong-Ou-Mandel interferences. Their study paves the way for quantum state engineering, quantum interferences, and logic operations in non-Hermitian photonic systems.
Xinchen Zhang et al.
Phys. Rev. A 109, L041503 (2024)
LETTER
The authors show that a resonator designed to operate at an absorbing exceptional point is substantially better at capturing a naturally emitted decaying waveform than a conventional cavity with a similar factor. This enhanced performance can lead to improved protocols for classical and quantum state transfer between resonant cavities.
Asaf Farhi et al.
Phys. Rev. A 109, L041502 (2024)
EDITORS' SUGGESTION
The authors study the interaction between two polar molecules in rotational states differing by two or more quanta. They find that the resultant repulsive van der Waals interaction can potentially suppress collisional losses at low temperatures.
Etienne F. Walraven and Tijs Karman
Phys. Rev. A 109, 043310 (2024)
LETTER
The work challenges the concept of “classical independence” between physical systems by demonstrating that within quantum theory two systems can affect each other despite no observable changes, unveiling the interconnected nature of the quantum world. The findings also unveil potential applications for device-independent certification of quantum states and measurements.
Shubhayan Sarkar
Phys. Rev. A 109, L040202 (2024)
LETTER
The authors derive bounds on the suppression of the bandwidth-integrated local density of states (LDOS). They show that effective one-dimensional gratings which support a slow light mode can achieve near-perfect LDOS suppression even in the presence of material loss.
Benjamin Strekha et al.
Phys. Rev. A 109, L041501 (2024)
LETTER
The authors find a harmonic enhancement structure in the high-order harmonic generation spectrum of graphene. Further investigation indicates that the structure is associated with the bunching of multiple interband electron-hole recombination trajectories, in analogy to the focusing behavior of light rays known as caustics.
Fulong Dong, Qinzhi Xia, and Jie Liu
Phys. Rev. A 109, L041102 (2024)
LETTER
The authors measure transverse spin correlations in energy space to uncover hidden spin dynamics in a weakly interacting Fermi gas. The correlation functions reveal the microscopic structure of a demagnetizing or magnetizing synthetic spin lattice, which models a collective Heisenberg Hamiltonian, and provide new observables for studies of transitions between dynamical phases.
J. Huang and J. E. Thomas
Phys. Rev. A 109, L041301 (2024)
LETTER
The authors unravel the complexities of nonlinear interference phenomena in laser-atom interaction, demonstrating the role of an electron as a carrier of the obscured fundamental frequencies inherent in the laser pulse. Through theoretical analysis, they identify how interactions between electrons and the concealed fundamental frequencies within intense laser pulses craft distinctive interference patterns and confinement effects in the momentum landscape, offering profound insights into the quantum dynamics underpinning ionization processes.
Danish Furekh Dar and Stephan Fritzsche
Phys. Rev. A 109, L041101 (2024)
EDITORS' SUGGESTION
The authors propose a Floquet qubit that is the superconducting circuit analog of a mechanical Kapitza pendulum. Under periodic driving, the bit and phase flip rates of the emerging qubit states are exponentially suppressed with respect to the ratio of the effective Josephson energy to charging energy. A cooling scheme to protect the system against charge noise is also proposed.
Zhaoyou Wang and Amir H. Safavi-Naeini
Phys. Rev. A 109, 042607 (2024)
PERSPECTIVE
The authors offer an overview of fundamental concepts in topological photonics and a categorization of recent advancements in this growing field across linear, nonlinear, and quantum regimes. They provide a detailed exploration of future directions, enduring challenges, and elusive questions surrounding the application of topological ideas in photonics systems.
Mahmoud Jalali Mehrabad, Sunil Mittal, and Mohammad Hafezi
Phys. Rev. A 108, 040101 (2023)