In this article we derive the exact dynamics of a two-qubit (spin $1/2$) system interacting centrally with separate spin baths composed of qubits in a thermal state. Furthermore, each spin of the bath is coupled to every other spin of the same bath. The corresponding dynamical map is constructed. It i…

[Phys. Rev. A 106, 032435] Published Fri Sep 30, 2022

]]>Estimating causal relations from observed correlations is a central content of science. Although a comprehensive mathematical framework has been developed to identify cause and effect, it is well known that such methods and techniques are not applicable to quantum systems due to Bell's theorem. Gene…

[Phys. Rev. A 106, 032436] Published Fri Sep 30, 2022

]]>A linear-optics network is a multimode interferometer system, where indistinguishable photon inputs can create nonclassical interference that cannot be simulated with classical computers. Such nonclassical interference implies the existence of entanglement among its subsystems if we divide its modes…

[Phys. Rev. A 106, 032437] Published Fri Sep 30, 2022

]]>We theoretically study the orientation dependence of even-order harmonics in biased bilayer graphene (BLG) by numerically solving the semiconductor Bloch equations in the velocity gauge. It is shown that the yield of even-order harmonics has a perfect periodicity of ${60}^{\circ}$ with the rotation of the crys…

[Phys. Rev. A 106, 033123] Published Fri Sep 30, 2022

]]>Conditional cooling-by-measurement holds a significant advantage over its unconditional (nonselective) counterpart in the average-population-reduction rate. However, it has a clear weakness with respect to the limited success probability of finding the detector in the measured state. In this work, w…

[Phys. Rev. A 106, 033124] Published Fri Sep 30, 2022

]]>Previous work on imaging wave-packet dynamics with x-ray scattering revealed that the scattering patterns deviate substantially from the notion of instantaneous momentum density of the wave packet. Here we show that scattering patterns can provide clear insights into the electron wave-packet dynamic…

[Phys. Rev. A 106, 033125] Published Fri Sep 30, 2022

]]>We study the radiative properties—the Lamb shift, Purcell decay rate, and spontaneous emission dynamics—of an artificial atom coupled to a long, multimode cavity formed by an array of Josephson junctions. Introducing a tunable coupling element between the atom and the array, we demonstrate that such…

[Phys. Rev. A 106, 033714] Published Fri Sep 30, 2022

]]>Building on work by Tsirelson, we present a family of protocols that detect the nonclassicality of suitable states of a single quantum system, under the sole assumption that the measured dynamical observable undergoes a uniform precession. The case of the harmonic oscillator was anticipated in the w…

[Phys. Rev. A 106, 032222] Published Thu Sep 29, 2022

]]>Calculations of molecular spectral properties, like photodissociation rates and absorption bands, rely on knowledge of the excited state energies of the molecule of interest. Protocols based on the variational quantum eigensolver (VQE) are promising candidates to calculate such energies on emerging …

[Phys. Rev. A 106, 032434] Published Thu Sep 29, 2022

]]>A simple model is proposed to compute electron-diatomic molecule elastic differential cross sections at intermediate energies within the framework of an analytical local optical potential. In a spherical harmonic expansion of the molecular potential we treat the isotropic term with the partial-wave …

[Phys. Rev. A 106, 032813] Published Thu Sep 29, 2022

]]>Attosecond dynamics in strong-field tunnel ionization are encoded in intricate holographic patterns in the photoelectron momentum distributions. These patterns show the interference between two or more superposed quantum electron trajectories, which are defined by their ionization times and subseque…

[Phys. Rev. A 106, 033118] Published Thu Sep 29, 2022

]]>The behavior of a twisted electron colliding with a linearly polarized laser pulse is investigated within relativistic quantum mechanics. In order to better fit the real experimental conditions, we introduce a Gaussian spatial profile for the initial electron state as well as an envelope function fo…

[Phys. Rev. A 106, 033119] Published Thu Sep 29, 2022

]]>Metal-corroles are macrocycle organic molecules with numerous practical applications. In particular, copper corroles exhibit an interesting saddled geometry, which has attracted significant attention from theoreticians and experimentalists over the years. The present work is dedicated to understand …

[Phys. Rev. A 106, 033120] Published Thu Sep 29, 2022

]]>The accurate evaluation of the second-order Doppler frequency shift (SODFS) of trapped ions in a linear Paul trap has been studied with experiments and molecular dynamics (MD) simulations. The motion of trapped ions in the trap has three contributions, and we focus on the ion excess micromotion, whi…

[Phys. Rev. A 106, 033121] Published Thu Sep 29, 2022

]]>In this paper, we apply the Monte Carlo wave packet method to study the ultrafast nuclear dynamics following inner-shell photoionization of ${\mathrm{N}}_{2}$ exposed to an ultrashort intense x-ray pulse. The intermediate states in ${\mathrm{N}}_{2}{}^{+}$ are highly excited so that autoionization takes place from these states to the q…

[Phys. Rev. A 106, 033122] Published Thu Sep 29, 2022

]]>We present the analysis of the structure of fermionic vortices with the spin-polarized core from a weak coupling limit to the unitary regime. We show the mechanism for the generation of the reversed circulation in the vortex core induced by an excess of majority spin particles. We introduce the clas…

[Phys. Rev. A 106, 033322] Published Thu Sep 29, 2022

]]>The $t-J$ Hamiltonian of the spinful hard-core bosonic ring in the Nagaoka limit is solved. The energy spectrum becomes quantized due to presence of spin, where each energy level corresponds to a cyclic permutation state of the spin chains. The ground state is true ferromagnetic when the ring contains…

[Phys. Rev. A 106, 033323] Published Thu Sep 29, 2022

]]>The interaction between the quantum emitter and topological photonic system makes both the emitter and the photon behave in exotic ways. We here study a system where a giant atom is coupled to two points of a one-dimensional topological waveguide formed by the Su-Schrieffer-Heeger (SSH) chain. The t…

[Phys. Rev. A 106, 033522] Published Thu Sep 29, 2022

]]>We consider a spatiotemporal differentiator of the first order based on a three-layer metal-dielectric-metal (MDM) structure. We show theoretically and numerically that, in contrast to all-dielectric layered structures, the differentiator based on this MDM structure enables generating an optical pul…

[Phys. Rev. A 106, 033523] Published Thu Sep 29, 2022

]]>Floquet engineering can induce complex collective behavior and an interesting synthetic gauge field in quantum systems through temporal modulation of the system parameters by periodic drives. Using a Floquet drive on frequencies of the magnon modes, we realize a chiral state transfer in a cavity-mag…

[Phys. Rev. A 106, 033711] Published Thu Sep 29, 2022

]]>We use a numerical method combining the cluster mean-field theory and the matrix product state to study the ground-state phase diagram of a one-dimensional two-qubit Dicke-Hubbard model with $XY$ qubit-qubit interaction. When counterrotating wave terms (CRTs) in the qubit-cavity coupling are neglected…

[Phys. Rev. A 106, 033712] Published Thu Sep 29, 2022

]]>Implementation of high-speed quantum key distribution (QKD) has become one of the major focuses in the field, which produces a high key-generation rate for applications. To achieve high-speed QKD, tailored techniques are developed and employed to quickly generate and detect quantum states. However, …

[Phys. Rev. A 106, 033713] Published Thu Sep 29, 2022

]]>In the work by Rebouças and Brandão [Phys. Rev. A **104**, 063514 (2021)] the authors compute the scattering amplitude for a $\mathcal{P}\mathcal{T}$-symmetric double-$\delta $-function potential in three dimensions by invoking the far-zone approximation and summing the resulting Born series. We show that the analysis of this paper …

[Phys. Rev. A 106, 037501] Published Thu Sep 29, 2022

]]>It is theoretically predicted that strong electromagnetic driving of an array of two-level atoms, coupled to a waveguide, can make quantum excitations of the array decay faster.

[Phys. Rev. A 106, L031702] Published Thu Sep 29, 2022

]]>We investigate the Loschmidt echo in a one-dimensional spin chain having Kitaev-type interaction in constant and kicked magnetic fields. The Loschmidt echo for the initial states having different magnon excitations shows long-time revivals for smaller chains and has short-time revival peaks for the …

[Phys. Rev. A 106, 032221] Published Wed Sep 28, 2022

]]>In this paper we provide a genuine relativistic quantum teleportation protocol the classical communication component of which makes use of relativistic causal propagation of a quantum field. Consequently, the quantum teleportation is fully relativistic by construction. Our scheme is based on the Unr…

[Phys. Rev. A 106, 032432] Published Wed Sep 28, 2022

]]>Random quantum circuit sampling, a task to sample bit strings from a random quantum circuit, is considered a suitable benchmark task to demonstrate the outperformance of quantum computers even with noisy qubits. Recently, random quantum circuit sampling was performed on the Sycamore quantum processo…

[Phys. Rev. A 106, 032433] Published Wed Sep 28, 2022

]]>Demonstrations of quantum advantage have largely focused on computational speedups and on quantum simulation of many-body physics, limited by fidelity and the capability of current devices. Discriminating laser-pulse-modulated classical-communication code words at the minimum allowable probability o…

[Phys. Rev. A 106, 032613] Published Wed Sep 28, 2022

]]>Coulomb effects in the high-energy part of photoelectron spectra produced through the above-threshold ionization of an atom subject to intense short laser pulses are analyzed. The analysis is carried out for linearly polarized and tailored bicircular laser pulses consisting of the fundamental and th…

[Phys. Rev. A 106, 033117] Published Wed Sep 28, 2022

]]>We theoretically explore a promising route to achieve the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state in a spin-imbalanced ultracold Fermi gas. In the current stage of cold atom physics, search for this exotic Fermi superfluid is facing two serious difficulties: One is the desperate destruction of…

[Phys. Rev. A 106, 033320] Published Wed Sep 28, 2022

]]>We present an approach to the Bose polaron based on the notion of quantum groups, also known as $q$-deformed Lie algebras. In this approach, a mobile impurity can be depicted as a deformation of the Lie algebra of the bosonic creation and annihilation operators of the bath, in which the impurity is im…

[Phys. Rev. A 106, 033321] Published Wed Sep 28, 2022

]]>Coherent quantum-noise cancellation (CQNC) can be used in optomechanical sensors to surpass the standard quantum limit (SQL). In this paper, we investigate an optomechanical force sensor that uses the CQNC strategy by cascading the optomechanical system with an all-optical effective negative-mass os…

[Phys. Rev. A 106, 033520] Published Wed Sep 28, 2022

]]>The Hilbert hotel is an old mathematical paradox about sets of infinite numbers. This paradox deals with the accommodation of a new guest in a hotel with an infinite number of occupied rooms. Over the past decade, there have been many attempts to implement these ideas in photonic systems. In additio…

[Phys. Rev. A 106, 033521] Published Wed Sep 28, 2022

]]>The Markovian and non-Markovian dynamics of quantum coherence, including single-spin coherence, two-spin coherence, and its distribution (collective and localized coherence), are investigated in the $XX$ spin chain with three-spin interaction. We find that the single-spin and localized coherence do no…

[Phys. Rev. A 106, 032220] Published Tue Sep 27, 2022

]]>Almost a century ago, it was proposed that solid hydrogen could become metallic at sufficiently high pressure. Five years back, scientists observed an insulator to metal transition in liquid deuterium experimentally, at around 300 $\mathrm{GPa}$. The present work discusses and demonstrates the metal-like behav…

[Phys. Rev. A 106, 032812] Published Tue Sep 27, 2022

]]>We provide a framework to solve generic models describing the dissociation of multiple molecular Bose-Einstein condensates in a nonadiabatic regime. The competition between individual chemical reactions can lead to nontrivial dependence on critical components such as path interference and symmetries…

[Phys. Rev. A 106, 033318] Published Tue Sep 27, 2022

]]>We experimentally and numerically demonstrate a method to generate multiply quantized superfluid circulation about an obstacle in highly oblate Bose-Einstein condensates (BECs). We experimentally achieve pinned superflow with winding numbers as high as 11, which persists for at least 4 s. Our method…

[Phys. Rev. A 106, 033319] Published Tue Sep 27, 2022

]]>Higher-order exceptional points (EPs) in non-Hermitian systems have attracted great interest due to their advantages in sensitive enhancement and distinct topological features. However, realization of such EPs is still a challenge because more fine-tuning parameters are generically required in quant…

[Phys. Rev. A 106, 033518] Published Tue Sep 27, 2022

]]>We report the observation of the thermalization of the Fermi-Pasta-Ulam-Tsingou recurrence process in optical fibers. We show the transition from a reversible regime to an irreversible one, revealing a spectrally thermalized state. To do so, we actively compensate the fiber loss to make the observat…

[Phys. Rev. A 106, 033519] Published Tue Sep 27, 2022

]]>Using an extended Tavis-Cummings model, we study the effect of the spin-orbit coupling between the singlet and the triplet molecular excitons in organic microcavities in the strong-coupling regime. The model is solved in the single excitation space for polaritons, which contains the bright (permutat…

[Phys. Rev. A 106, 033709] Published Tue Sep 27, 2022

]]>Understanding and manipulating the excitation transport lie in the center of the research of various mesoscopic quantum devices. Here, we study the exciton transport in a one-dimensional two-level systems chain described by the Su-Schrieffer-Heeger Hamiltonian. Without cavity, the dimerization-assis…

[Phys. Rev. A 106, 033710] Published Tue Sep 27, 2022

]]>The authors propose and explore a quantum heat engine based on a Bose-Einstein condensate with spin-orbit and Zeeman couplings as a working medium where the cooling and heating are simulated by the condensate contact with an external magnetized and demagnetized media. This study of the quantum thermal machine could help understand the basic principles of quantum thermodynamics.

[Phys. Rev. A 106, L030201] Published Tue Sep 27, 2022

]]>There is a pressing need to develop new rechargeable battery technologies that can offer higher energy storage, faster charging, and lower costs. Despite the success of existing methods for the simulation of battery materials, they can sometimes fall short of delivering accurate and reliable results…

[Phys. Rev. A 106, 032428] Published Mon Sep 26, 2022

]]>The increasing success of classical generative adversarial networks (GANs) has inspired several quantum versions of GANs. Fully quantum mechanical applications of such quantum GANs have been limited to one- and two-qubit systems. In this paper, we investigate the entangling quantum GAN (EQ-GAN) for …

[Phys. Rev. A 106, 032429] Published Mon Sep 26, 2022

]]>Quantum teleportation provides a way to transfer unknown quantum states from one system to another via an entangled state as a quantum channel without physical transmission of the object itself. The entangled channel, measurement performed by the sender (Alice), and classical information sent to the…

[Phys. Rev. A 106, 032430] Published Mon Sep 26, 2022

]]>Fault-tolerant quantum computation relies on scaling up quantum error correcting codes in order to suppress the error rate on the encoded quantum states. Topological codes, such as the surface code or color codes, are leading candidates for practical scalable quantum error correction and require eff…

[Phys. Rev. A 106, 032431] Published Mon Sep 26, 2022

]]>A two-dimensional Fock-state lattice (FSL) is constructed from the many-body states of two interacting two-mode quantum gases. By periodically driving the interspecies interactions and pulsing the tunneling between the two modes of each gas, a synthetic gauge field is generated. We derive an effecti…

[Phys. Rev. A 106, 033317] Published Mon Sep 26, 2022

]]>Optical forces in dielectric structures are typically analyzed by utilizing either the Maxwell stress tensor or energy-based methods from which they can be derived by means of the eigenfrequencies and the effective refractive indices involved. While the equivalence of these two methods has been disc…

[Phys. Rev. A 106, 033517] Published Mon Sep 26, 2022

]]>Converse symmetry breaking is a phenomenon occurring in populations of coupled oscillators, where stable and phase-locked symmetric states are possible only if the system itself is not symmetric. In this Letter, the analogy of converse symmetry breaking with amplification processes caused by phase and loss asymmetry for signal and idler waves in nonlinear optical systems is presented.

[Phys. Rev. A 106, L031505] Published Mon Sep 26, 2022

]]>The authors describe an experimental scheme capable of simultaneously demonstrating signatures of quantum theory and general relativity by using entangled multiphoton states to measure space-time curvature. The setup allows for curvature measurements at altitudes smaller than those required for classical or single-photon measurements.

[Phys. Rev. A 106, L031701] Published Mon Sep 26, 2022

]]>Bell nonlocality represents one of the most striking departures of quantum mechanics from classical physics. It shows that correlations between spacelike separated systems allowed by quantum mechanics are stronger than those present in any classical theory. In a recent work [A. Tavakoli, M. Farkas, …

[Phys. Rev. A 106, 032219] Published Fri Sep 23, 2022

]]>Observation of vibrational Feshbach resonances in the annihilation spectra of positrons on molecules provides a direct measurement of the positron-molecule binding energy ${\varepsilon}_{B}$. Annihilation measurements are presented for ring hydrocarbons with different numbers of $\pi $ bonds, for which it is observed tha…

[Phys. Rev. A 106, 032811] Published Fri Sep 23, 2022

]]>We report measurements of the absolute photoionization cross sections of magnesiumlike ${\mathrm{S}}^{4+}$ over the 158–280 eV photon energy range. The experiments were performed with the multianalysis ion apparatus at the SOLEIL synchrotron radiation facility. Single- and double-ionization ion yields produced by t…

[Phys. Rev. A 106, 033113] Published Fri Sep 23, 2022

]]>Postcollision-interaction (PCI) effects involving multistep decay processes following Ar $1s$ photoionization has been studied by Auger electron spectroscopy. The experiment focused on $LMM$ Auger electrons measured in small photon energy steps across the Ar $1s$ photoionization threshold. Decay pathways …

[Phys. Rev. A 106, 033114] Published Fri Sep 23, 2022

]]>The complicated collisional processes inside a femtosecond laser-induced plasma column can show a great impact on the light emissions from it. A known example is that the lifetime of noncoherent fluorescence emitting from gas plasma can be greatly decreased due to the fierce ultrafast plasma collisi…

[Phys. Rev. A 106, 033115] Published Fri Sep 23, 2022

]]>We investigate theoretically the photoelectron holography in strong-field ionization by a few-cycle chirped laser pulse. It is shown that the numerical results by solving the two-dimensional (2D) time-dependent Schrödinger equation (TDSE) are in agreement with that by using the semiclassical two-ste…

[Phys. Rev. A 106, 033116] Published Fri Sep 23, 2022

]]>We show that the higher-order soliton evolution can be considerably affected by the relative positions of the zero-nonlinearity wavelength (ZNW) and zero-dispersion wavelength (ZDW) with respect to the input wavelength in photonic crystal fibers (PCFs) with frequency-dependent Kerr nonlinearity. By …

[Phys. Rev. A 106, 033516] Published Fri Sep 23, 2022

]]>A model of charge separation in quantum photosynthesis as a model of quantum feedback control in a system of interacting excitons and vibrons is introduced. In this approach quantum feedback induces a nonlinear evolution equation which describes the Landau-Zener transition with decoherence and can b…

[Phys. Rev. A 106, 032218] Published Thu Sep 22, 2022

]]>We propose a way to measure the qubit state of an arbitrary subensemble of atoms in an array without significantly disturbing the quantum information in the unmeasured atoms. The idea is to first site-selectively transfer atoms out of the qubit basis so that one of the two states at a time is put in…

[Phys. Rev. A 106, 032425] Published Thu Sep 22, 2022

]]>The current stage of quantum computing technology, called noisy intermediate-scale quantum technology, is characterized by large errors that prohibit it from being used for real applications. In these devices, decoherence, one of the main sources of error, is generally modeled by Markovian master eq…

[Phys. Rev. A 106, 032426] Published Thu Sep 22, 2022

]]>Solving a quadratic nonlinear system of equations (QNSE) is a fundamental, but important, task in nonlinear science. We propose an efficient quantum algorithm for solving $n$-dimensional QNSE. Our algorithm embeds QNSE into a finite-dimensional system of linear equations using the homotopy perturbatio…

[Phys. Rev. A 106, 032427] Published Thu Sep 22, 2022

]]>Light carrying time-varying orbital angular momentum (OAM) is a recently discovered type of structured electromagnetic field compared with a typical vortex field whose OAM is static. Such so-called self-torqued light is employed for manipulating the fast magnetic, topological, and quantum excitation…

[Phys. Rev. A 106, 033515] Published Thu Sep 22, 2022

]]>The Aharonov-Bohm (AB) effect is a pure quantum effect that implies a measurable phase shift in the wave function for a charged particle that encircles a magnetic flux located in a region *inaccessible* to the particle. Classically, such a nonlocal effect appears to be impossible since the Lorentz for…

[Phys. Rev. A 106, 032217] Published Wed Sep 21, 2022

]]>We consider the clock game–a task formulated in the framework of quantum information theory—that can be used to improve the existing schemes of quantum-enhanced telescopy. The problem of learning when a stellar photon reaches a telescope is translated into an abstract game, which we call the clock g…

[Phys. Rev. A 106, 032424] Published Wed Sep 21, 2022

]]>Quantum multiple parameter estimation can achieve an enhanced sensitivity beyond the classical limit. Although a theoretical ultimate sensitivity bound for multiple phase estimation is given by the quantum Cramer-Rao bound (QCRB), experimental implementations to saturate the QCRB typically require a…

[Phys. Rev. A 106, 032612] Published Wed Sep 21, 2022

]]>This paper investigates theoretically the effect of nonreciprocity on surface electromagnetic waves (SEWs) propagating in magneto-optical structures in mutually opposite directions, i.e., on waves with tangential wave numbers $k$ of opposite sign. Namely, of our interest is a correlation between the n…

[Phys. Rev. A 106, 033513] Published Wed Sep 21, 2022

]]>We present an inverse-design approach to significantly improve the figures of merit for chiral photonics with quantum emitters in topological photonic crystal slab waveguides. Beginning with a topological waveguide mode with a group index of approximately 10 and a maximum forward or backward Purcell…

[Phys. Rev. A 106, 033514] Published Wed Sep 21, 2022

]]>We propose that weak continuous probing may be exploited to determine and define quantum phases of complex many-body systems based on the measurement record alone. We test the resulting phase criterion in numerical simulations of measurements on the Bose-Hubbard model and the quantum Ising chain. Th…

[Phys. Rev. A 106, 032215] Published Tue Sep 20, 2022

]]>It has been found that in certain non-Hermitian Hamiltonian systems, all the eigenstates can have their amplitudes concentrating to the open boundaries of the systems and decaying exponentially into the bulk, which is totally different from their counterparts in Hermitian systems. This phenomenon ha…

[Phys. Rev. A 106, 032216] Published Tue Sep 20, 2022

]]>Quantitative characterization of different entanglement detection criteria for bipartite systems is presented. We review the implication sequence of these criteria and then numerically estimate volume ratios between criteria nonviolating quantum states and all quantum states. The numerical approach …

[Phys. Rev. A 106, 032423] Published Tue Sep 20, 2022

]]>First-principle calculations are employed to investigate the ultrafast isomerization of the acetylene cation and dication. We use the time-dependent density functional theory together with the Ehrenfest dynamics to track the coupled electron-nuclear dynamics. For both the acetylene cation and the di…

[Phys. Rev. A 106, 033111] Published Tue Sep 20, 2022

]]>We experimentally study the angular distribution of near-threshold photoelectrons of argon in the multiphoton-ionization regime. Those near-threshold photoelectrons are released from atoms by a weak 800-nm laser field and a strong 400-nm laser field with parallel polarizations. In the laser polariza…

[Phys. Rev. A 106, 033112] Published Tue Sep 20, 2022

]]>Spatial light modulation is important for many scientific and industrial applications. The spatial light modulator and optical data projector both rely on precisely configurable optical elements to shape a light beam. Here we explore an image-projection approach which does not require a configurable…

[Phys. Rev. A 106, 033512] Published Tue Sep 20, 2022

]]>The classical and quantum theories leading to the asymptotic Bethe formula of the stopping power of matter for charged particles heavier than the electron are briefly reviewed. Models and approximations for the practical calculation of various corrections that extend the validity range of the formul…

[Phys. Rev. A 106, 032809] Published Mon Sep 19, 2022

]]>We calculate elastic and positronium (Ps) break-up cross sections for collisions of Ps with the polar molecules CO, HCl, and LiF in the fixed-nuclei approximation. We incorporate electron exchange and correlation for these processes by using the free-electron-gas model developed earlier for Ps scatt…

[Phys. Rev. A 106, 032810] Published Mon Sep 19, 2022

]]>Imaging laser-induced rotational dynamics is an important and active field due to its applications in capturing reactions in the molecular frame and in molecular imaging. Experimental measurement of the molecular orientation distribution, as a function of the Euler angles, has been demonstrated for …

[Phys. Rev. A 106, 033109] Published Mon Sep 19, 2022

]]>We experimentally demonstrate an externally seeded ${\mathrm{N}}_{2}{}^{+}$ lasing action on the transition between the $B{\phantom{\rule{4pt}{0ex}}}^{2}{\mathrm{\Sigma}}_{u}{}^{+}\left(v=0\right)$ and $X{\phantom{\rule{4pt}{0ex}}}^{2}{\mathrm{\Sigma}}_{g}{}^{+}\left({v}^{\prime}=0\right)$ states at 391.4 nm by irradiating a ${\mathrm{N}}_{2}$ gas with an intense 400-nm pump laser pulse and reveal that the populations in the rotational levels of ${J}^{\prime}=7\u201317$ in the $B{\phantom{\rule{4pt}{0ex}}}^{2}{\mathrm{\Sigma}}_{u}{}^{+}\left(v=0\right)$ state…

[Phys. Rev. A 106, 033110] Published Mon Sep 19, 2022

]]>The authors propose a non-Hermitian Hamiltonian to describe the resonances of photonic crystal slabs formed by coupled high-index contrast gratings. This model can potentially enable the discovery of novel photonic specie through the manipulation of bound states in the continuum and exceptional points. The authors then demonstrate experimentally, as proof-of-concept, the formation of a Dirac point at the merging of three bound states in the continuum.

[Phys. Rev. A 106, 033510] Published Mon Sep 19, 2022

]]>Focused structured light fields with spatially nonuniform correlation can exhibit multiple focal points in the longitudinal direction, which suggests that they are suitable for longitudinal optical trapping. Due to the controllable nature of the longitudinal intensity distribution, this class of str…

[Phys. Rev. A 106, 033511] Published Mon Sep 19, 2022

]]>The parametrically pumped Kerr model describes a driven-dissipative nonlinear cavity, whose nonequilibrium phase diagram features both continuous and discontinuous quantum phase transitions. We consider the consequences of these critical phenomena for the fluctuations of the photocurrent obtained vi…

[Phys. Rev. A 106, 033707] Published Mon Sep 19, 2022

]]>We propose to control spin-mixing dynamics in a gas of spinor atoms, via the combination of two off-resonant Raman transition pathways, enabled by a common cavity mode and a bichromatic pump laser. The mixing rate, which is proportional to the synthesized spin-exchange interaction strength, and the …

[Phys. Rev. A 106, 033708] Published Mon Sep 19, 2022

]]>The authors experimentally investigate the optical properties of single chlorine donor atoms within a zinc-selenide quantum well. They show that donor-bound excitons are a stable source of single photons with a fast radiative lifetime on the order of 200 ps.

[Phys. Rev. A 106, L030402] Published Mon Sep 19, 2022

]]>Linear optics imposes a relation that is more general than the second law of thermodynamics: For modes undergoing a linear evolution, the full mean occupation number, i.e., the photon number for optical modes, does not decrease, provided the evolution starts from a (generalized) diagonal state. This…

[Phys. Rev. A 106, 032214] Published Fri Sep 16, 2022

]]>In quantum state discrimination, one aims to identify unknown states from a given ensemble by performing measurements. Different strategies such as minimum-error discrimination or unambiguous state identification find different optimal measurements. Maximum-confidence measurements (MCMs) maximize th…

[Phys. Rev. A 106, 032422] Published Fri Sep 16, 2022

]]>We demonstrate that several metastable excited states in Hf ii, Hf iv, and W vi ions may be good clock states since they are sufficiently long-living and are not sensitive to the perturbations. The cooling electric dipole ($E1$) transition is available for Hf ii, while sympathetic cooling is possible …

[Phys. Rev. A 106, 032807] Published Fri Sep 16, 2022

]]>Experiments dedicated to the measurement of the electric dipole moment of the neutron require outstanding control of the magnetic-field uniformity. The neutron electric dipole moment (nEDM) experiment at the Paul Scherrer Institute uses a ${}^{199}\mathrm{Hg}$ co-magnetometer to precisely monitor temporal magnetic-…

[Phys. Rev. A 106, 032808] Published Fri Sep 16, 2022

]]>We introduce a procedure to generate supersinglets, the multipartite generalization of angular momentum singlet states. A supersinglet is defined as a total spin zero state consisting of $N$ spin-$j$ particles. They are highly entangled and have zero spin variance in any direction, and as such are poten…

[Phys. Rev. A 106, 033314] Published Fri Sep 16, 2022

]]>Ultracold spinor atoms in the weak and strong interaction regimes have been extensively investigated, while the behavior in the intermediate regime is less understood. We numerically investigate one-dimensional ultracold spinor atomic ensembles of finite size in the intermediate interaction regime a…

[Phys. Rev. A 106, 033315] Published Fri Sep 16, 2022

]]>We consider large rings of weakly coupled Bose-Einstein condensates, analyzing their transition to chaotic dynamics and loss of coherence. Initially, a ring is considered to be in an eigenstate, i.e., in a commensurate configuration with equal site fillings and equal phase differences between neighb…

[Phys. Rev. A 106, 033316] Published Fri Sep 16, 2022

]]>We exploit the interplay between uncertainty, disturbance, nonlocality, and self-duality within the framework of generalized probabilistic theories (GPTs). We first introduce an operational uncertainty-disturbance relation that reveals the discrepancies of GPTs in uncertainty and disturbance exhibit…

[Phys. Rev. A 106, 032213] Published Thu Sep 15, 2022

]]>Two spatially separated observers, Alice and Bob, share a bipartite two-qubit entangled state and perform measurements to witness entanglement. After their measurements, they pass their qubits to a subsequent pair of observers who try to perform the same task independently, and so on. Here we ask: w…

[Phys. Rev. A 106, 032419] Published Thu Sep 15, 2022

]]>Filter methods realize a projection from a superposed quantum state onto a target state, which can be efficient if two states have sufficient overlap. Here we propose a quantum Gaussian filter (QGF) with the filter operator being a Gaussian function of the system Hamiltonian. A hybrid quantum-classi…

[Phys. Rev. A 106, 032420] Published Thu Sep 15, 2022

]]>One notion of nonlocality in quantum theory is the fact that information may be encoded in a composite system in such a way that it is not accessible through local measurements, even with the assistance of classical communication. Thus, contrary to the classical case, there exists information in qua…

[Phys. Rev. A 106, 032421] Published Thu Sep 15, 2022

]]>The direct counterfactual quantum-communication protocol involving double-chained Mach-Zehnder interferometers requires a single-photon input. Here, we show that even with multiphoton light sources, including a strong coherent light source as input, the counterfactual communication can be achieved w…

[Phys. Rev. A 106, 032610] Published Thu Sep 15, 2022

]]>We derive an integral expression for the filter-transfer function of an arbitrary one-qubit gate through the use of dynamical invariant theory and Hamiltonian reverse engineering. We use this result to define a cost function which can be efficiently optimized to produce one-qubit control pulses that…

[Phys. Rev. A 106, 032611] Published Thu Sep 15, 2022

]]>Molecular photoelectron spectra are commonly obtained theoretically in Fermi's Golden Rule framework, where the stationary continuum wave function is represented by slowly converging series such as the celebrated partial wave expansion. In this paper, we employ an alternative approach to address the…

[Phys. Rev. A 106, 032806] Published Thu Sep 15, 2022

]]>Grover multiports are higher-dimensional generalizations of beam splitters, in which input to any one of the four ports has equal probability of exiting at any of the same four ports, including the input port. In this paper, we demonstrate that interferometers built from such multiports have novel f…

[Phys. Rev. A 106, 033706] Published Thu Sep 15, 2022

]]>The authors find that tuning a cavity to an absorbing exceptional point, in which eigenvalues and eigenmodes coalesce, results in an expansion of the class of waveforms that can be perfectly captured by the system. As a result, such cavities can impedance match to an optimal transient input signal at least an order of magnitude better.

[Phys. Rev. A 106, L031503] Published Thu Sep 15, 2022

]]>The authors introduce new measures of directional emission in microcavity lasers by exploiting the notion of Shannon entropy, and suggest that an entropic measure of the unidirectional emission is more accurate and efficient than former measures.

[Phys. Rev. A 106, L031504] Published Thu Sep 15, 2022

]]>We propose a cavity Heisenberg-spin-chain (CHS) quantum battery (QB) with the long-range interactions and investigate its charging process. The performance of the CHS QB is substantially improved compared to the Heisenberg spin chain (HS) QB. When the number of spins $N\gg 1$, the quantum advantage $\alpha $ of …

[Phys. Rev. A 106, 032212] Published Wed Sep 14, 2022

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