Einstein-Podolsky-Rosen (EPR) steering, as a new form of nonlocality, stands between entanglement and Bell nonlocality, implying promising applications for quantum information tasks. The problem of detecting EPR steering plays an important role in characterization of quantum nonlocality. Despite som…

[Phys. Rev. A 95, 032128] Published Fri Mar 24, 2017

]]>A map between the problems of boson sampling and simulating the evolution of interacting spins is established. By enabling the use of physical systems other than traditional optical circuits as quantum simulators, this work increases the odds of proving quantum supremacy.

[Phys. Rev. A 95, 032327] Published Fri Mar 24, 2017

]]>Long-lived isotopes of plutonium were studied using two complementary techniques, high-resolution resonance ionization spectroscopy (HR-RIS) and collinear laser spectroscopy (CLS). Isotope shifts have been measured on the $5{f}^{6}7{s}^{2}{\phantom{\rule{4pt}{0ex}}}^{7}{F}_{0}\to 5{f}^{5}6{d}^{2}7s\phantom{\rule{4pt}{0ex}}(J=1)$ and $5{f}^{6}7{s}^{2}{\phantom{\rule{4pt}{0ex}}}^{7}{F}_{1}\to 5{f}^{6}7s7p\phantom{\rule{4pt}{0ex}}(J=2)$ atomic transitions using th…

[Phys. Rev. A 95, 032506] Published Fri Mar 24, 2017

]]>We study the formation of the RbCs molecule by an intense laser pulse using nonlinear dynamics. Under the Born-Oppenheimer approximation, the system is modeled by a two-degree-of-freedom rovibrational Hamiltonian, which includes the ground electronic potential energy curve of the diatomic molecule a…

[Phys. Rev. A 95, 033424] Published Fri Mar 24, 2017

]]>We study the fidelity decay and its freeze for an initial coherent state of two-mode Bose-Einstein condensates in the Fock regime considering a Bose-Hubbard model that includes two-particle tunneling terms. By using linear-response theory we find scaling properties of the fidelity as a function of t…

[Phys. Rev. A 95, 033624] Published Fri Mar 24, 2017

]]>We present a method for calculating the dynamics of a bosonic mixture, the multicomponent correlated-basis-function (CBF) method. For a single component, CBF results for the excitation energies agree quite well with experimental results, even for highly correlated systems like ${}^{4}\mathrm{He}$, and recent system…

[Phys. Rev. A 95, 033625] Published Fri Mar 24, 2017

]]>We study the time evolution of a Bose-Einstein condensate with a vortex on it when it is released from a trap and expands freely in a spatially uncorrelated disordered media. As customary in such cases, we perform the evolution over different disorder realizations and average over the disorder to ob…

[Phys. Rev. A 95, 033626] Published Fri Mar 24, 2017

]]>We present a theory of cooperative light scattering valid in any dimension: connecting theories for an open line, open plane, and open space in the nonrelativistic regime. This theory includes near-field and dipole-orientation effects, highlighting how field-mode confinement controls the phenomena. …

[Phys. Rev. A 95, 033832] Published Fri Mar 24, 2017

]]>We examine the switching dynamics of discrete solitons propagating along two coupled discrete arrays which are twisted to form a Möbius strip. We analyze the potential of the topological switches by comparing the differences between the Möbius strip and untwisted discrete arrays. We employ the Ablow…

[Phys. Rev. A 95, 033833] Published Fri Mar 24, 2017

]]>We investigate the transient dynamics of photon statistics through two-time correlation functions for optical field coupled to a non-Markovian environment, described by the Fano-type Hamiltonian. We exactly solve the time-evolution of an initially nonclassical state which exhibits photon antibunchin…

[Phys. Rev. A 95, 033830] Published Thu Mar 23, 2017

]]>We study theoretically two-photon states in a periodic array of coupled cavities with both on-site and nonlocal Kerr-type nonlinearities. In the absence of nonlinearity the structure is topologically trivial and possesses no edge states. The interplay of two nonlinear interaction mechanisms describe…

[Phys. Rev. A 95, 033831] Published Thu Mar 23, 2017

]]>Almost one and a half centuries ago, Abbe [Arch. Mikrosk. Anat. **9**, 413 (1873)] and shortly after Lord Rayleigh [Philos. Mag. Ser. 5 **8**, 261 (1879)] showed that, when an optical lens is illuminated by a plane wave, a diffraction-limited spot with radius $0.61\lambda /sin\alpha $ is obtained, where $\lambda $ is the wavelengt…

[Phys. Rev. A 95, 031802(R)] Published Wed Mar 22, 2017

]]>A many-body Wannier-Stark system coupled to an effective reservoir is studied within a non-Hermitian approach in the presence of a periodic driving. We show how the interplay of dissipation and driving dynamically induces a subspace of states which are very robust against dissipation. We numerically…

[Phys. Rev. A 95, 032125] Published Wed Mar 22, 2017

]]>Theoretical description and simulation of large quantum coherent systems out of equilibrium remains a daunting task. Here we are developing an approach to it based on the Pechukas-Yukawa formalism, which is especially convenient in the case of an adiabatically slow external perturbation, though it i…

[Phys. Rev. A 95, 032126] Published Wed Mar 22, 2017

]]>We quantify the intrinsic noise content of an observable in a general probabilistic theory and derive a noise content inequality for incompatible observables. We apply the derived inequality to standard quantum theory, the quantum theory of processes, and polytope state spaces. The noise content for…

[Phys. Rev. A 95, 032127] Published Wed Mar 22, 2017

]]>The traveling-salesman problem is an iconic route-finding task, with applications from chip design to planning and logistics. Here the authors show that if the graph of cities to be visited is of low degree, a traveling salesman armed with a quantum satnav can find the best route quadratically faster than using any known classical method.

[Phys. Rev. A 95, 032323] Published Wed Mar 22, 2017

]]>We examine two proposals for marginally-self-correcting quantum memory: the cubic code by Haah and the welded code by Michnicki. In particular, we prove explicitly that they are absent of topological order above zero temperature, as their Gibbs ensembles can be prepared via a short-depth quantum cir…

[Phys. Rev. A 95, 032324] Published Wed Mar 22, 2017

]]>We show how to calculate the secure final key rate in the four-intensity decoy-state measurement-device-independent quantum key distribution protocol with both source errors and statistical fluctuations with a certain failure probability. Our results rely only on the range of only a few parameters i…

[Phys. Rev. A 95, 032325] Published Wed Mar 22, 2017

]]>We formulate a general family of entanglement criteria for multipartite states on arbitrary Hilbert spaces. Fisher information criteria compare the sensitivity to unitary rotations with the variances of suitable local observables. Generalized squeezing-type criteria provide lower bounds that are les…

[Phys. Rev. A 95, 032326] Published Wed Mar 22, 2017

]]>We determine effective collisional radii of positronium (Ps) by considering Ps states in hard-wall spherical cavities. $B$-spline basis sets of electron and positron states inside the cavity are used to construct the states of Ps. Accurate Ps energy eigenvalues are obtained by extrapolation with respe…

[Phys. Rev. A 95, 032705] Published Wed Mar 22, 2017

]]>We show that the processes of $\pi -{\pi}^{*}$ transitions imprint themselves on the high-harmonic spectra when conjugated molecules interact with intense femtosecond laser pulses. It is found that a noninteger order peak appears in the harmonic spectrum with the photon energy equaling the excitation energy of …

[Phys. Rev. A 95, 033421] Published Wed Mar 22, 2017

]]>The dynamics of ${\mathrm{CO}}_{2}$ excited into Rydberg states lying 0.2 eV below the ionization threshold is studied by means of time resolved photoelectron imaging. Over 3 eV broad photoelectron spectra are measured for all pump-probe delay times. Quantum mechanical calculations demonstrate that the spectral bro…

[Phys. Rev. A 95, 033422] Published Wed Mar 22, 2017

]]>Using analogies from cavity steady-state superradiance, an experimental scheme for mesoscopic collective steady-state spin synchronization is proposed with ion-trap systems, where the synchronization in the primary species of ions is mediated by the dissipation of a normal vibrational mode induced by sympathetic cooling with the secondary species of ions.

[Phys. Rev. A 95, 033423] Published Wed Mar 22, 2017

]]>The purpose of this paper is to investigate system identification for single-input–single-output general (active or passive) quantum linear systems. For a given input we address the following questions: (1) Which parameters can be identified by measuring the output? (2) How can we construct a system…

[Phys. Rev. A 95, 033825] Published Wed Mar 22, 2017

]]>Motivated by new technologies for designing and tailoring metamaterials, we seek properties for certain classes of nonlinear optical materials that allow room for a reversibly controlled opacity-to-transparency phase transition through the application of external electromagnetic fields. We examine s…

[Phys. Rev. A 95, 033826] Published Wed Mar 22, 2017

]]>A technique for implementing rather arbitrary transformations on the spatial structure of a high-dimensional light field is proposed. The method employs multiple spatial phase modulation stages and free-space propagation, hence promising a simple, fixed, and scalable setup.

[Phys. Rev. A 95, 033827] Published Wed Mar 22, 2017

]]>We observe time-correlated emission between a single CdSe/CdS/ZnS quantum dot exhibiting single-photon statistics and a fluorescent nanobead located micrometers apart. This is accomplished by coupling both emitters to a silver nanowire. Single plasmons are created on the latter from the quantum dot,…

[Phys. Rev. A 95, 033828] Published Wed Mar 22, 2017

]]>We investigate the dynamics of a coupled waveguide system with competing linear and nonlinear loss-gain profiles which can facilitate power saturation. We show the usefulness of the model in achieving unidirectional beam propagation. In this regard, the considered type of coupled waveguide system ha…

[Phys. Rev. A 95, 033829] Published Wed Mar 22, 2017

]]>Insulating glass capillaries have been shown to lead to ion transmission without any change in either the ion charge state or in the ion kinetic energy. This surprising process has been attributed to a self-organized distribution of charge patches creating the necessary guiding electric potential on…

[Phys. Rev. A 95, 030702(R)] Published Tue Mar 21, 2017

]]>In order to clarify the physics underlying the observations of the electronlike behavior of positronium (Ps) and its resonant scattering from ${\mathrm{CO}}_{2}$, we have measured the $\text{Ps}+{\mathrm{N}}_{2}$ total cross section and found it also to exhibit significant structure. Analysis of the resonances reveals that Ps is distorte…

[Phys. Rev. A 95, 032704] Published Tue Mar 21, 2017

]]>High-order-harmonic generation in the interaction of femtosecond lasers with atoms and molecules opens the path to molecular-orbital tomography and to probe the electronic dynamics with attosecond-Ångström resolutions. Molecular-orbital tomography requires both the amplitude and phase of the high-or…

[Phys. Rev. A 95, 033420] Published Tue Mar 21, 2017

]]>We study nonlinear mixing effects among quadrupole modes and scissors modes in a harmonically trapped Bose-Einstein condensate. Using a perturbative technique in conjunction with a variational approach with a Gaussian trial wave function for the Gross-Pitaevskii equation, we find that mode mixing oc…

[Phys. Rev. A 95, 033623] Published Tue Mar 21, 2017

]]>Deuteron momentum distributions from the dissociative ionization of ${\mathrm{D}}_{2}$ in intense elliptically polarized laser fields have been explored in a joint experimental and numerical study. The asymmetrical charge localization in the dissociative ${{\mathrm{D}}_{2}}^{+}$ offers a large torque, and thus an elliptically polarized…

[Phys. Rev. A 95, 031404(R)] Published Mon Mar 20, 2017

]]>It is a well-known fact that both quantum entanglement and nonlocality (implied by the violation of Bell inequalities) constitute quantum correlations that cannot be arbitrarily shared among subsystems. They are both monogamous, albeit in a different fashion. In the present contribution we focus on …

[Phys. Rev. A 95, 032123] Published Mon Mar 20, 2017

]]>James' effective Hamiltonian method has been extensively adopted to investigate largely detuned interacting quantum systems. This method only corresponds to the second-order perturbation theory and cannot be exploited to treat problems which should be solved by using the third- or higher-order pertu…

[Phys. Rev. A 95, 032124] Published Mon Mar 20, 2017

]]>The simultaneous multiparameter estimation problem using a class of multimode entangled states is investigated in this paper. Specifically, the problem of optical phase imaging is considered, and the quantum probe is taken to be a balanced coherent superposition of components with an arbitrary quant…

[Phys. Rev. A 95, 032321] Published Mon Mar 20, 2017

]]>We analyze theoretically spontaneous parametric down-conversion in a multimode nonlinear waveguide as a source of entangled pairs of spatial qubits, realized as superpositions of a photon in two orthogonal transverse modes of the waveguide. It is shown that, by exploiting intermodal dispersion, down…

[Phys. Rev. A 95, 032322] Published Mon Mar 20, 2017

]]>Agreement between theoretical calculations of atomic structure and spectroscopic measurements is used to constrain possible contribution of exotic spin-dependent interactions between electrons to the energy differences between states in helium-4. In particular, constraints on dipole-dipole interacti…

[Phys. Rev. A 95, 032505] Published Mon Mar 20, 2017

]]>The potential scattering of electrons carrying nonzero quanta of the orbital angular momentum (OAM) is studied in a framework of the generalized Born approximation, developed in our recent paper [D. V. Karlovets, G. L. Kotkin, and V. G. Serbo, Phys. Rev. A **92**, 052703 (2015)]. We treat these so-calle…

[Phys. Rev. A 95, 032703] Published Mon Mar 20, 2017

]]>We measure multi-orbital contributions to high harmonic generation from aligned nitrogen. We show that the change in revival structure in the cutoff harmonics has a counterpart in the angular distribution when a lower-lying orbital contributes to the harmonic yield. This angular distribution is dire…

[Phys. Rev. A 95, 033419] Published Mon Mar 20, 2017

]]>We theoretically analyze the ground state of weakly interacting bosons in the flux ladder—the system that has been recently realized by means of ultracold atoms in the specially designed optical lattice [M. Atala, M. Aidelsburger, M. Lohse, J. T. Barreiro, B. Paredes, and I. Bloch, Nat. Phys. **10**, 58…

[Phys. Rev. A 95, 033622] Published Mon Mar 20, 2017

]]>High-order sideband generation in an optomechanical system coupled to a charged object is discussed, and the features of Coulomb-interaction-dependent effect are identified. We show that the Coulomb-interaction-dependent effect of high-order sideband generation exhibits essential difference between …

[Phys. Rev. A 95, 033820] Published Mon Mar 20, 2017

]]>We report a method of generating atomic density gratings by standing-wave manipulation of ultracold Bose gases. By illuminating the gratings with a beam of homogeneous light, we observe one- and two-dimensional Talbot carpets. We further measure the autocorrelation function of the images, which vari…

[Phys. Rev. A 95, 033821] Published Mon Mar 20, 2017

]]>We compute the reflectance properties of a metasurface that consists of a doubly periodic array of patch nanoantennas strongly coupled to a metallic film. Each plasmonic patch antenna can be accurately modeled as a polarizable, radiating, magnetic dipole. By accounting for interactions amongst the d…

[Phys. Rev. A 95, 033822] Published Mon Mar 20, 2017

]]>An optical field with orbital angular momentum (OAM) has many remarkable properties due to its unique azimuthal phase, showing many potential applications in high-capacity information processing such as terabit free-space data transmission, and high-precision measurement such as high sensitivity of …

[Phys. Rev. A 95, 033823] Published Mon Mar 20, 2017

]]>Based on the plane-wave expansion method, we have analytically obtained a set of higher-order transverse magnetic (TM) modes that can exist on a metal-dielectric interface. Any linear combination of these modes can be supported on the interface. Our analysis is based on the assumption of nonuniformi…

[Phys. Rev. A 95, 033824] Published Mon Mar 20, 2017

]]>Bell nonlocality can be formulated in terms of a resource theory with local-hidden variable models as resourceless objects. Two such theories are known, one built upon local operations assisted by shared randomness (LOSRs) and the other one allowing, in addition, for prior-to-input classical communi…

[Phys. Rev. A 95, 032118] Published Fri Mar 17, 2017

]]>The non-Markovian Langevin approach is applied to study the dynamics of fermionic (bosonic) oscillator linearly coupled to a fermionic (bosonic) environment. The analytical expressions for occupation numbers in two different types of couplings (rotating-wave approximation and fully coupled) are comp…

[Phys. Rev. A 95, 032119] Published Fri Mar 17, 2017

]]>Simulating quantum nonlocality and steering requires augmenting preshared randomness with nonvanishing communication cost. This prompts the question of how one may provide such an operational characterization for the quantumness of correlations due to even unentangled states. Here we show that for a…

[Phys. Rev. A 95, 032120] Published Fri Mar 17, 2017

]]>In a previous article [Phys. Rev. Lett. **117**, 213201 (2016)] we have determined the angular resolved and the total energy spectrum of a positron produced via nonlinear Breit-Wheeler pair production by a high-energy photon counterpropagating with respect to a tightly focused laser beam. Here, we first…

[Phys. Rev. A 95, 032121] Published Fri Mar 17, 2017

]]>Testing quantum theory on macroscopic scales is a longstanding challenge whose solution could have a significant impact on physics. For example, laboratory tests (such as those anticipated in nanomechanical or biological systems) may look to rule out macroscopic realism: the idea that the properties…

[Phys. Rev. A 95, 032122] Published Fri Mar 17, 2017

]]>Many scenarios in the sciences and engineering require simultaneous optimization of multiple objective functions, which are usually conflicting or competing. In such problems the Pareto front, where none of the individual objectives can be further improved without degrading some others, shows the tr…

[Phys. Rev. A 95, 032319] Published Fri Mar 17, 2017

]]>Orbital angular momentum of photons is an intriguing system for the storage and transmission of quantum information, but it is rapidly degraded by atmospheric turbulence. Understanding the noise processes that affect photons is essential if we desire to protect them. In this paper we use the infinit…

[Phys. Rev. A 95, 032320] Published Fri Mar 17, 2017

]]>Isotope shifts and total transition frequencies are calculated for the $2\phantom{\rule{0.16em}{0ex}}{}^{2}S-3\phantom{\rule{0.16em}{0ex}}{}^{2}S$ transition of the lithium isotopes ${}^{6}\mathrm{Li},{}^{7}\mathrm{Li},{}^{8}\mathrm{Li},{}^{9}\mathrm{Li}$, and the halo nucleus ${}^{11}\mathrm{Li}$. The accuracy is improved for previously calculated relativistic and quantum electrodynamic corrections, and in particular a disagreement fo…

[Phys. Rev. A 95, 032504] Published Fri Mar 17, 2017

]]>Photoionization cross sections and photoelectron angular distribution asymmetry parameters are calculated for the $4{d}^{10},\phantom{\rule{0.16em}{0ex}}5{s}^{2},\phantom{\rule{0.16em}{0ex}}5{p}^{6}$, and $6{s}^{2}$ subshells of atomic barium as a test of the relativistic multiconfiguration Tamm-Dancoff (RMCTD) method. The shape resonance present in the near-threshold region of…

[Phys. Rev. A 95, 033417] Published Fri Mar 17, 2017

]]>We analyze the mechanism of THz generation in a gas medium with intense two-color infrared lasers pulses. The dependence of the amplitude of THz emission on the relative phase between the fundamental color (800 nm) and its second harmonic (400 nm) is shown to be identical to the residual current as …

[Phys. Rev. A 95, 033418] Published Fri Mar 17, 2017

]]>Vacuum consists of a bath of balanced and symmetric positive- and negative-frequency fluctuations. Media in relative motion or accelerated observers can break this symmetry and preferentially amplify negative-frequency modes as in quantum Cherenkov radiation and Unruh radiation. Here, we show the ex…

[Phys. Rev. A 95, 033817] Published Fri Mar 17, 2017

]]>Based on a formalism that describes atom-light interactions in terms of the classical electromagnetic Green's function, we study the optical response of atoms and other quantum emitters coupled to one-dimensional photonic structures, such as cavities, waveguides, and photonic crystals. We demonstrat…

[Phys. Rev. A 95, 033818] Published Fri Mar 17, 2017

]]>We present an extension of the Gerchberg-Saxton algorithm to allow for phase retrieval from interferometric data recorded at multiple sample-detector distances. A system of coupled waves is introduced where the information exchange can be controlled by use of relaxation parameters. Optimal parameter…

[Phys. Rev. A 95, 033819] Published Fri Mar 17, 2017

]]>A unified view of the phenomenon of monogamy exhibited by Bell inequalities and noncontextuality inequalities arising from the no-signaling and no-disturbance principles is presented using the graph-theoretic method introduced by Ramanathan *et al.* [Phys. Rev. Lett. **109**, 050404 (2012)]. We propose a …

[Phys. Rev. A 95, 030104(R)] Published Thu Mar 16, 2017

]]>We experimentally demonstrate the strictly nonclassical behavior in a many-atom system using a recently derived criterion [E. Kot *et al.*, Phys. Rev. Lett. **108**, 233601 (2012)] that explicitly does not make use of quantum mechanics. We thereby show that the magnetic-moment distribution measured by Mc…

[Phys. Rev. A 95, 030105(R)] Published Thu Mar 16, 2017

]]>The dynamics of systems subjected to noise is called Markovian in the absence of memory effects, i.e., when its immediate future depends only on its present. Time correlations in the noise source may generate non-Markovian effects that, sometimes, can be erased by appropriately coarse graining the t…

[Phys. Rev. A 95, 032117] Published Thu Mar 16, 2017

]]>Use of time delays in high-order-harmonic generation (HHG) driven by intense two-color, few-cycle pulses is investigated in order to determine means of optimizing HHG intensities and plateau cutoff energies. Based upon numerical solutions of the time-dependent Schrödinger equation for the H atom as …

[Phys. Rev. A 95, 033413] Published Thu Mar 16, 2017

]]>The *ab initio* description of the nonlinear response of many-electron systems to strong-laser fields remains a major challenge. In order to address larger systems, alternative methods need to be developed that bypass the exponential scaling with particle number inherent to conventional wave-function-…

[Phys. Rev. A 95, 033414] Published Thu Mar 16, 2017

]]>High-order-harmonic generation (HHG) results from the interaction of ultrashort laser pulses with matter. It configures an invaluable tool to produce attosecond pulses, moreover, to extract electron structural and dynamical information of the target, i.e., atoms, molecules, and solids. In this contr…

[Phys. Rev. A 95, 033415] Published Thu Mar 16, 2017

]]>A scheme for achieving high temporal resolution in gas electron diffraction is proposed, in which time-dependent electron diffraction patterns can be obtained from energy-resolved angular distributions of electrons scattered by molecules in dynamical processes under the presence of a single-cycle TH…

[Phys. Rev. A 95, 033416] Published Thu Mar 16, 2017

]]>We develop an exact approach to study the quench dynamics of hard-core bosons initially in thermal equilibrium in one-dimensional lattices. This approach is used to study the sudden expansion of thermal states after confining potentials are switched off. We find that a dynamical fermionization of th…

[Phys. Rev. A 95, 033617] Published Thu Mar 16, 2017

]]>In this work we discuss the Landau criterion for anisotropic superfluidity. To this end we consider a pointlike impurity moving in a uniform Bose-Einstein condensate with either interparticle dipole-dipole interaction or Raman-induced spin-orbit coupling. In both cases we find that the Landau critic…

[Phys. Rev. A 95, 033618] Published Thu Mar 16, 2017

]]>We consider the thermodynamic potential $\mathrm{\Omega}$ of an $N$ component Fermi gas with a short-range interaction obeying $\mathrm{SU}\left(N\right)$ symmetry. We analyze especially the nonanalytic part of $\mathrm{\Omega}$ in the temperature $T$ at low $T$. We examine the temperature range where one can observe this ${T}^{4}lnT$ contribution and discuss how i…

[Phys. Rev. A 95, 033619] Published Thu Mar 16, 2017

]]>We study a quasispin-1/2 Bose-Einstein condensate with synthetically generated spin-orbit coupling in a toroidal trap and show that the system has a rich variety of ground states. As the central hole region increases, i.e., the potential changes from harmoniclike to ringlike, the condensate exhibits…

[Phys. Rev. A 95, 033620] Published Thu Mar 16, 2017

]]>We offer interferometry models for thermal ensembles with one-body losses and the phenomenological inclusion of perturbations covering most of the thermal atom experiments. A possible extension to the many-body case is briefly discussed. The Ramsey pulses are assumed to have variable durations and t…

[Phys. Rev. A 95, 033621] Published Thu Mar 16, 2017

]]>We show that temporal reflections off a moving refractive index barrier play a major role in the spectral broadening of a dual-wavelength input inside a highly nonlinear, dispersion-decreasing fiber. We also find that a recently developed linear theory of temporal reflections works well in predictin…

[Phys. Rev. A 95, 033813] Published Thu Mar 16, 2017

]]>The long-standing goal of deterministic quantum interactions between single photons and single atoms was recently realized in various experiments. Among these, an appealing demonstration relied on single-photon Raman interaction (SPRINT) in a three-level atom coupled to a single-mode waveguide. In e…

[Phys. Rev. A 95, 033814] Published Thu Mar 16, 2017

]]>We theoretically model pair generation and evolution via the nonlinear process of spontaneous four-wave mixing in a coupled-resonator optical waveguide in a photonic crystal slab. Using the adjoint master equation for a system of lossy coupled cavities, we calculate a symmetrized second-order cohere…

[Phys. Rev. A 95, 033815] Published Thu Mar 16, 2017

]]>We establish that a connection exists between wave-particle duality of photons and partial polarization of a light beam. We perform a two-path lowest-order (single photon) interference experiment and demonstrate both theoretically and experimentally that the degree of polarization of the light beam …

[Phys. Rev. A 95, 033816] Published Thu Mar 16, 2017

]]>The paradox of Greenberger-Horne-Zeilinger (GHZ) disproves directly the concept of EPR elements of reality, based on the EPR correlations, in an all-versus-nothing way. A three-qubit experimental demonstration of the GHZ paradox was achieved nearly 20 years ago, followed by demonstrations for more q…

[Phys. Rev. A 95, 030103(R)] Published Wed Mar 15, 2017

]]>We study photon creation in a cavity with two perfectly conducting moving mirrors. We derive the dynamic equations of the modes and study different situations concerning various movements of the walls, such as translational or breathing modes. We can even apply our approach to one- or three-dimensio…

[Phys. Rev. A 95, 032115] Published Wed Mar 15, 2017

]]>Two recent experiments studying the potential effect of entanglement on the emission properties of excited atoms produced in molecular photodissociation have been interpreted in conflicting ways. We present a theoretical analysis of the problem, showing that the experimental results can be explained…

[Phys. Rev. A 95, 032116] Published Wed Mar 15, 2017

]]>We reported a detailed experimental study of the cold collision of barium monofluoride (BaF) with buffer gas and the high-resolution spectroscopy relevant with direct laser cooling. BaF molecules are efficiently produced with laser ablation and buffer-gas cooled in a cryogenic apparatus. The laser c…

[Phys. Rev. A 95, 032701] Published Wed Mar 15, 2017

]]>We investigate the long-range, two-body interactions between rubidium and potassium atoms in highly excited $(n=70)$ Rydberg states. After establishing properly symmetrized asymptotic basis states, we diagonalize an interaction Hamiltonian consisting of the standard Coulombic potential expansion and a…

[Phys. Rev. A 95, 032702] Published Wed Mar 15, 2017

]]>We report on a realization of sub-Doppler laser cooling of ${}^{39}\mathrm{K}$ atoms using degenerate three-dimensional Raman sideband cooling. We take advantage of the well-resolved excited hyperfine states on the ${D}_{1}$ optical transition to produce spin-polarized samples with $1.4\times {10}^{8}$ atoms at temperatures of 1.8 $\mu \mathrm{K}$.…

[Phys. Rev. A 95, 033412] Published Wed Mar 15, 2017

]]>Artificial gauge fields are versatile tools that allow the dynamics of ultracold atoms in Bose-Einstein condensates to be influenced. Here we discuss a method of artificial gauge field generation stemming from the evanescent fields of the curved surface of an optical nanofiber. The exponential decay…

[Phys. Rev. A 95, 033615] Published Wed Mar 15, 2017

]]>We investigate the collective excitations of a Raman-induced spin-orbit coupled Bose-Einstein condensate confined in a quasi-one-dimensional harmonic trap using the Bogoliubov method. By tuning the Raman coupling strength, three phases of the system can be identified. By calculating the transition s…

[Phys. Rev. A 95, 033616] Published Wed Mar 15, 2017

]]>We study the behavior of a single laser-driven trapped ion inside a microscopic optical Fabry-Perot cavity. In particular, we demonstrate a fiber Fabry-Perot cavity operating on the principal ${S}_{1/2}\to {P}_{1/2}$ electric dipole transition of an ${\mathrm{Yb}}^{+}$ ion at 369 nm with an ion-cavity coupling strength of $g=2\pi \times 67\dots $

[Phys. Rev. A 95, 033812] Published Wed Mar 15, 2017

]]>Similarly to how charged particles experience time-averaged ponderomotive forces in high-frequency fields, linear waves also experience time-averaged refraction in modulated media. Here we propose a covariant variational theory of this ponderomotive effect on waves for a general nondissipative linea…

[Phys. Rev. A 95, 032114] Published Tue Mar 14, 2017

]]>We study magnetic solitons, solitary waves of spin polarization (i.e., magnetization), in binary Bose-Einstein condensates in the presence of Rabi coupling. We show that the system exhibits two types of magnetic solitons, called $2\pi $ and $0\pi $ solitons, characterized by a different behavior of the relati…

[Phys. Rev. A 95, 033614] Published Tue Mar 14, 2017

]]>We propose and experimentally implement an efficient procedure based on entanglement swapping to determine the Bell nonlocality measure of Horodecki *et al.* [Phys. Lett. A **200**, 340 (1995)] and the fully entangled fraction of Bennett *et al.* [Phys. Rev. A **54**, 3824 (1996)] of an arbitrary two-qubit pola…

[Phys. Rev. A 95, 030102(R)] Published Mon Mar 13, 2017

]]>We combine near-deterministic preparation of a single atom with Raman sideband cooling, to create a push-button mechanism to prepare a single atom in the motional ground state of tightly focused optical tweezers. In the two-dimensional (2D) radial plane, we achieve a large ground-state fidelity for …

[Phys. Rev. A 95, 031403(R)] Published Mon Mar 13, 2017

]]>Nondestructive weak measurements (WMs) made on a quantum particle are useful in order to extract information as the particle evolves from a prepared state to a finally detected state. The physical meaning of this information has been open to debate, particularly in view of the apparent discontinuous…

[Phys. Rev. A 95, 032110] Published Mon Mar 13, 2017

]]>Bound entanglement, being entangled yet not distillable, is essential to our understanding of the relations between nonlocality and entanglement besides its applications in certain quantum information tasks. Recently, bound entangled states that violate a Bell inequality have been constructed for a …

[Phys. Rev. A 95, 032111] Published Mon Mar 13, 2017

]]>Continuous spontaneous localization (CSL) is a model that captures the effects of a class of extensions to quantum theory which are expected to result from quantum gravity and is such that wave-function collapse is a physical process. The rate of such a process could be very much lower than the uppe…

[Phys. Rev. A 95, 032112] Published Mon Mar 13, 2017

]]>We provide a very simple case showing that the weak form of the Heisenberg limit can be beaten while the prior information is improved without bias.

[Phys. Rev. A 95, 032113] Published Mon Mar 13, 2017

]]>The strong subadditivity inequality of von Neumann entropy relates the entropy of subsystems of a tripartite state ${\rho}_{ABC}$ to that of the composite system. Here, we define ${\mathit{T}}^{\left(a\right)}\left({\rho}_{ABC}\right)$ as the extent to which ${\rho}_{ABC}$ fails to satisfy the strong subadditivity inequality $S\left({\rho}_{B}\right)+S\left({\rho}_{C}\right)\le S\left({\rho}_{AB}\right)+S\left({\rho}_{AC}\right)$ with equality…

[Phys. Rev. A 95, 032315] Published Mon Mar 13, 2017

]]>We propose fast phase gates of single nuclear spins interacting with single electron spins. The gate operation utilizes geometric phase shifts of the electron spin induced by fast and slow rotating fields; the path difference depending on nuclear-spin states enables nuclear phase shifts. The gate ti…

[Phys. Rev. A 95, 032316] Published Mon Mar 13, 2017

]]>We analyze the operation of a four-qubit Bacon-Shor code with simultaneous continuous measurement of noncommuting gauge operators. The error syndrome in this case is monitored via time-averaged cross-correlators of the output signals. We find the logical error rate for several models of decoherence,…

[Phys. Rev. A 95, 032317] Published Mon Mar 13, 2017

]]>Network centrality has important implications well beyond its role in physical and information transport analysis; as such, various quantum-walk-based algorithms have been proposed for measuring network vertex centrality. In this work, we propose a continuous-time quantum walk algorithm for determin…

[Phys. Rev. A 95, 032318] Published Mon Mar 13, 2017

]]>An extremely rare candidate of nuclear transition which can be driven by optical lasers exists in the ${}^{229}$Th isotope. Internal conversion of the long-lived, excited nuclear state from an electronically excited ${}^{229}$Th ionic state is proposed as a means to observe and characterize this transition.

[Phys. Rev. A 95, 032503] Published Mon Mar 13, 2017

]]>The weak-field asymptotic theory (WFAT) and the Born-Oppenheimer approximation (BOA) provide two general approaches to the theory of tunneling ionization of molecules enabling one to treat the internuclear motion quantum mechanically on an equal footing with the electronic motion. The approaches are…

[Phys. Rev. A 95, 033410] Published Mon Mar 13, 2017

]]>We investigate above-threshold ionization (ATI) of homonuclear diatomic molecules by the so-called bicircular field using the improved molecular strong-field approximation. Bicircular field is a two-color laser field having coplanar circularly polarized counter-rotating components of frequencies $r\omega $ …

[Phys. Rev. A 95, 033411] Published Mon Mar 13, 2017

]]>We study the superconducting properties of population-imbalanced ultracold Fermi mixtures in one-dimensional optical lattices that can be effectively described by the spin-imbalanced attractive Hubbard model in the presence of a Zeeman magnetic field. We use the mean-field theory approach to obtain …

[Phys. Rev. A 95, 033613] Published Mon Mar 13, 2017

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