Bell's theorem states that quantum mechanics is not a locally causal theory. This state is often interpreted as nonlocality in quantum mechanics. Toner and Bacon [Phys. Rev. Lett. **91**, 187904 (2003)] have shown that a shared random-variable theory augmented by one bit of classical communication exact…

[Phys. Rev. A 92, 052119] Published Wed Nov 25, 2015

]]>In quantum theory, a physical observable is represented by a Hermitian operator as it admits real eigenvalues. This stems from the fact that any measuring apparatus that is supposed to measure a physical observable will always yield a real number. However, the reality of an eigenvalue of some operat…

[Phys. Rev. A 92, 052120] Published Wed Nov 25, 2015

]]>Evolutional entanglement production is defined as the amount of entanglement produced by the evolution operator. This quantity is analyzed for systems whose Hamiltonians are characterized by spin operators. The evolutional entanglement production at the initial stage grows quadratically in time. For…

[Phys. Rev. A 92, 052121] Published Wed Nov 25, 2015

]]>Stopping powers of antiprotons in ${\text{H}}_{2}$ and ${\text{H}}_{2}\text{O}$ targets are calculated using a semiclassical time-dependent convergent close-coupling method. In our approach the ${\text{H}}_{2}$ target is treated using a two-center molecular multiconfiguration approximation, which fully accounts for the electron-electron correlatio…

[Phys. Rev. A 92, 052711] Published Wed Nov 25, 2015

]]>The electron and photon scattering data of an atom are crucial for many scientific fields, including plasma physics, astrophysics, and so on. For high enough but nonrelativistic incident energies, the first Born approximation is applicable for calculating these data, in which the key physics quantit…

[Phys. Rev. A 92, 052712] Published Wed Nov 25, 2015

]]>Fast radiative cooling of anthracene cations ${\left({\mathrm{C}}_{14}{\mathrm{H}}_{10}\right)}^{+}$ is studied with a compact electrostatic storage device, the Mini-Ring. The time evolution of the internal energy distribution of the stored ions is probed in a time range from 3 to 7 ms using laser-induced dissociation with 3.49-eV photons. The …

[Phys. Rev. A 92, 053425] Published Wed Nov 25, 2015

]]>We study a problem of nonadiabatic superfluid dynamics of spin-orbit-coupled neutral fermions in two spatial dimensions. We focus on the two cases when the out-of-equilibrium conditions are initiated by either a sudden change of the pairing strength or the population imbalance. For the case of a zer…

[Phys. Rev. A 92, 053626] Published Wed Nov 25, 2015

]]>Conditions for stationary currents in a $\mathcal{P}\phantom{\rule{0}{0ex}}\mathcal{T}$-symmetric, non-Hermitian system are studied in the presence of degeneracy, where it is found that the general absence of such currents can be reverted by having a nonlinear interaction in systems such as Bose-Einstein condensates.

[Phys. Rev. A 92, 053627] Published Wed Nov 25, 2015

]]>Semiconductor microcavities with artificial single-photon emitters have become one of the backbones of semiconductor quantum optics. In many cases, however, technical and physical issues limit the study of optical fields to incoherently excited systems. We analyze the model of an incoherently driven…

[Phys. Rev. A 92, 053857] Published Wed Nov 25, 2015

]]>In this work we present a theoretical model of the tunneling time and the tunneling process (in attosecond experiment for the He atom). Our model is supported with physical reasoning leading to a relation which performs an excellent estimation for the tunneling time in attosecond and strong-field ex…

[Phys. Rev. A 92, 052118] Published Tue Nov 24, 2015

]]>We investigate the effect of noisy channels in a classical information transfer through a multipartite state which acts as a substrate for the distributed quantum dense coding protocol between several senders and *two* receivers. The situation is qualitatively different from the case with one or more …

[Phys. Rev. A 92, 052330] Published Tue Nov 24, 2015

]]>We present two quantum union bounds for sequential projective measurements. These bounds estimate the disturbance accumulation and probability of outcomes when the measurements are performed sequentially. These results are based on a trigonometric representation of quantum states and should have wid…

[Phys. Rev. A 92, 052331] Published Tue Nov 24, 2015

]]>Quantum entanglement is analyzed thoroughly in the case of the ground and lowest states of two-electron axially symmetric quantum dots under a perpendicular magnetic field. The individual-particle and the center-of-mass representations are used to study the entanglement variation at the transition f…

[Phys. Rev. A 92, 052332] Published Tue Nov 24, 2015

]]>We investigate multiqubit permutation-symmetric states with maximal entropy of entanglement. Such states can be viewed as particular spin states, namely anticoherent spin states. Using the Majorana representation of spin states in terms of points on the unit sphere, we analyze the consequences of a …

[Phys. Rev. A 92, 052333] Published Tue Nov 24, 2015

]]>A numerically cheap way to obtain structural information about clusters of rare gas atoms at low temperatures is developed. The semiclassical frozen-Gaussian imaginary-time propagator is extended such that it can account for the mean values of all interatomic distances in the cluster and their varia…

[Phys. Rev. A 92, 052519] Published Tue Nov 24, 2015

]]>In the free three-dimensional space, we consider a pair of identical $\uparrow $ fermions of some species or in some internal state and a pair of identical $\downarrow $ fermions of another species or in another state. There is a resonant $s$-wave interaction (that is, of zero range and infinite scattering length) between …

[Phys. Rev. A 92, 053624] Published Tue Nov 24, 2015

]]>Point defects in self-assembled crystals, such as vacancies and interstitials, attract each other and form stable clusters. This leads to a phase separation between perfect crystalline structures and defect conglomerates at low temperatures. We propose a method that allows one to tune the effective …

[Phys. Rev. A 92, 053625] Published Tue Nov 24, 2015

]]>A thin conducting sheet—graphene, for example—transmits, absorbs, and reflects radiation. A sheet that is very thin, even vanishingly so, can still produce 50% absorption at normal incidence if it has conductivity corresponding to half the impedance of free space. We find that, regardless of the she…

[Phys. Rev. A 92, 053856] Published Tue Nov 24, 2015

]]>Rydberg blockade at $n\sim 300$, is examined using strontium $n\phantom{\rule{0.16em}{0ex}}{}^{1}F_{3}$ Rydberg atoms excited in an atomic beam in a small volume defined by two tightly focused crossed laser beams. The observation of blockade for such states is challenging due to their extreme sensitivity to stray fields and the many magnetic …

[Phys. Rev. A 92, 051402(R)] Published Mon Nov 23, 2015

]]>Surprisingly often decoherence is due to classical fluctuations of ambient fields and may thus be described in terms of random unitary (RU) dynamics. However, there are decoherence channels where such a representation cannot exist. Based on a simple and intuitive geometric measure for the distance o…

[Phys. Rev. A 92, 052117] Published Mon Nov 23, 2015

]]>We present methods for the direct characterization of quantum dynamics in which both the principal and ancilla systems undergo noisy processes. Using a concatenated error detection code, we discriminate between located and unlocated errors on the principal system in what amounts to filtering of anci…

[Phys. Rev. A 92, 052329] Published Mon Nov 23, 2015

]]>The dipole polarizabilities, dipole hyperpolarizabilities, quadrupole moments, and quadrupole polarizabilities of the $5{s}^{2}\phantom{\rule{0.16em}{0ex}}{}^{1}S$ and $5s5p\phantom{\rule{0.16em}{0ex}}{}^{3}{P}^{o}$ states of ${\mathrm{In}}^{+}$ and Sr are calculated by using the finite-field method. The electron correlation effect and the basis set convergence are investigated in the relativi…

[Phys. Rev. A 92, 052515] Published Mon Nov 23, 2015

]]>Excitation energies, term designations, $g$ factors, transition rates, and lifetimes of ${\mathrm{U}}^{2+}$ are determined using a relativistic configuration interaction (CI) + linearized-coupled-cluster (LCC) approach. The CI-LCC energies are compared with CI + many-body-perturbation-theory (MBPT) and available expe…

[Phys. Rev. A 92, 052516] Published Mon Nov 23, 2015

]]>The long-range interaction between an antiprotonic helium atom $\overline{p}{\mathrm{He}}^{+}$ and helium atom in its ground state is studied. We calculate the dispersion coefficients ${C}_{6}$ using the complex coordinate rotation (CCR) formalism in order to comply with the resonant nature of metastable states of the antiprotonic …

[Phys. Rev. A 92, 052517] Published Mon Nov 23, 2015

]]>We compare the physical information contained in the Temkin-Poet (TP) scattering wave function representing electron-impact ionization of hydrogen, calculated by the convergent close-coupling (CCC) and generalized Sturmian function (GSF) methodologies. The idea is to show that the ionization cross s…

[Phys. Rev. A 92, 052518] Published Mon Nov 23, 2015

]]>We present an accurate theoretical model for the charge dependence of kinetic energy transferred in collisions between slow highly charged ions (HCIs) and the atoms in a carbon solid. The model is in excellent agreement with experimental kinetic-energy-loss data for carbon nanomembrane and thin carb…

[Phys. Rev. A 92, 052710] Published Mon Nov 23, 2015

]]>We theoretically study the control of photoelectron interference of atoms ionized by a two-color laser field with parallel polarizations. Based on both the quantum-trajectory Monte Carlo model and an *ab initio* simulation with numerically solving the time-dependent Schrödinger equation, we show that …

[Phys. Rev. A 92, 053422] Published Mon Nov 23, 2015

]]>We propose a protocol for measurement of the phonon number distribution of a harmonic oscillator based on selective mapping to a discrete spin-1/2 degree of freedom. We consider a system of a harmonically trapped ion, where a transition between two long-lived states can be driven with resolved motio…

[Phys. Rev. A 92, 053423] Published Mon Nov 23, 2015

]]>Free-electron lasers (FELs) produce short and very intense light pulses in the XUV and x-ray regimes. We investigate the possibility to drive Rabi oscillations in xenon with an intense FEL pulse by using the unusually large dipole strength of the giant dipole resonance (GDR). The GDR decays within l…

[Phys. Rev. A 92, 053424] Published Mon Nov 23, 2015

]]>Motivated by experiments exploring the physics of neutral atoms in artificial magnetic fields, we study the ground state of bosons interacting with long-range *dipolar* interactions on a two-leg ladder. We focus on the limit where the number of particles per site is large and the interactions are weak…

[Phys. Rev. A 92, 053623] Published Mon Nov 23, 2015

]]>This paper demonstrates the application of a polarization current approach to estimate the yield of soft x-ray Cherenkov radiation when a charged particle travels in the vicinity of a finite-size screen. To account for resonant anomalous dispersion of the complex permittivity, we apply the formalism…

[Phys. Rev. A 92, 053851] Published Mon Nov 23, 2015

]]>We evaluate a method, based on the near-field properties of surface-plasmon polaritons, to significantly enhance the dissipative optomechanical backaction mechanism. Although the large momentum of the surface-plasmon-polariton modes leads to the enhanced sensitivity of the scattering to the mechanic…

[Phys. Rev. A 92, 053852] Published Mon Nov 23, 2015

]]>We present the total transmission effect of inhomogeneous electromagnetic waves between dissipative media. The total transmission of a $p$-polarized plane wave at the interface between two lossless dielectrics happens at the Brewster angle. However, when a dielectric-conductor interface is considered,…

[Phys. Rev. A 92, 053853] Published Mon Nov 23, 2015

]]>The Manakov model is the simplest multicomponent model of nonlinear wave theory: It describes elementary stable soliton propagation and multisoliton solutions, and it applies to nonlinear optics, hydrodynamics, and Bose-Einstein condensates. It is also of fundamental interest as an asymptotic model …

[Phys. Rev. A 92, 053854] Published Mon Nov 23, 2015

]]>Self-pulsing cavity solitons may exist in a semiconductor laser with an intracavity saturable absorber. They show locally the passive $Q$-switching behavior that is typical of lasers with saturable absorbers in the plane-wave approximation. Here we show that excitable cavity solitons are also possible…

[Phys. Rev. A 92, 053855] Published Mon Nov 23, 2015

]]>Some remarks and numerics on TE waves guided in nonlinear media are presented. Connections with resent publications are discussed.

[Phys. Rev. A 92, 057803] Published Mon Nov 23, 2015

]]>The preceding Comment contains statements that we feel are inaccurate and that lead one to think that the problem we study in Phys. Rev. A **91**, 013840 (2015) was solved long ago. However, we argue that our results are new and add to the understanding of the process of transverse electric wave propaga…

[Phys. Rev. A 92, 057804] Published Mon Nov 23, 2015

]]>[Phys. Rev. A 92, 059903] Published Mon Nov 23, 2015

]]>We investigate the dissipative dynamics of a corotating vortex pair in a highly oblate axisymmetric Bose-Einstein condensate trapped in a harmonic potential. The initial vortex state is prepared by creating a doubly charged vortex at the center of the condensate and letting it dissociate into two si…

[Phys. Rev. A 92, 051601(R)] Published Fri Nov 20, 2015

]]>We examine the accuracy of an intrinsically one-dimensional (1D) quantum electrodynamics to predict accurately the forces and charges of a three-dimensional (3D) system that has a high degree of symmetry and therefore depends effectively only on a single coordinate. As a test case we analyze two cha…

[Phys. Rev. A 92, 052115] Published Fri Nov 20, 2015

]]>We consider a thermofield approach to analyze the evolution of an open quantum system coupled to an environment at finite temperature. In this approach, the finite-temperature environment is exactly mapped onto two virtual environments at zero temperature. These two environments are then unitarily t…

[Phys. Rev. A 92, 052116] Published Fri Nov 20, 2015

]]>In a variant of communication complexity tasks, two or more separated parties cooperate to compute a function of their local data, using a limited amount of communication. It is known that communication of quantum systems and shared entanglement can increase the probability for the parties to arrive…

[Phys. Rev. A 92, 052326] Published Fri Nov 20, 2015

]]>We investigate how to enhance entanglement in the steady state of interacting two-level systems. The steady state is reached by spontaneous decay of the individual systems. When we additionally couple them to a dissipative two-level ancilla with variable eigenfrequency and coupling strength, we obse…

[Phys. Rev. A 92, 052327] Published Fri Nov 20, 2015

]]>We study the relation between single-mode nonclassicality and two-mode entanglement in a beam splitter. We show that single-mode nonclassicality (the entanglement potential) of incident light cannot be transformed into two-mode entanglement completely after a single beam splitter. Some of the entang…

[Phys. Rev. A 92, 052328] Published Fri Nov 20, 2015

]]>We measured the ground-state static electric-dipole polarizabilities of Cs, Rb, and K atoms using a three-nanograting Mach-Zehnder atom beam interferometer. Our measurements provide benchmark tests for atomic structure calculations and thus test the underlying theory used to interpret atomic parity-…

[Phys. Rev. A 92, 052513] Published Fri Nov 20, 2015

]]>We present an *ab initio* approach for grand-canonical ensembles in thermal equilibrium (eq) with local or nonlocal external potentials based on the one-reduced density matrix (1RDM). We show that equilibrium properties of a grand-canonical ensemble are determined uniquely by the eq-1RDM and establish…

[Phys. Rev. A 92, 052514] Published Fri Nov 20, 2015

]]>The process of inelastic nonresonant two x-ray free-electron laser (XFEL) photon Compton scattering by a free atom is theoretically investigated. The object of the study is the He atom. We obtain the absolute values and the shape of the double differential scattering cross section. The quantum effec…

[Phys. Rev. A 92, 052709] Published Fri Nov 20, 2015

]]>The importance of multielectron dynamics during the tunneling ionization of a correlated quantum system is investigated. By comparison of the solution of the time-dependent Schrödinger equation with the time-dependent configuration-interaction singles approach, we demonstrate the importance of a mul…

[Phys. Rev. A 92, 053421] Published Fri Nov 20, 2015

]]>We introduce a two-dimensional short-range correlated disorder that is the natural generalization of the well-known one-dimensional dual random dimer model [D. H. Dunlap *et al.*, Phys. Rev. Lett. **65**, 88 (1990)]. We demonstrate that, as in one dimension, this model induces a localization-delocalizati…

[Phys. Rev. A 92, 053622] Published Fri Nov 20, 2015

]]>Anisotropic homogeneous metamaterials that are neither wholly dissipative nor wholly active at a specific frequency are permitted by classical electromagnetic theory. Well-established homogenization formalisms indicate that such a metamaterial may be realized quite simply as a random mixture of elec…

[Phys. Rev. A 92, 053847] Published Fri Nov 20, 2015

]]>Maxwell's fish eye is predicted to image with a resolution not limited by the wavelength of light. However, interactions between sources and drains may ruin the subwavelength imaging capabilities of this and similar absolute optical instruments. Nevertheless, as we show in this paper, at resonance f…

[Phys. Rev. A 92, 053848] Published Fri Nov 20, 2015

]]>We consider the effect of self-phase modulation and cross-phase modulation on the joint spectral amplitude of photon pairs generated by spontaneous four-wave mixing. In particular, the purity of a heralded photon from a pair is considered in the context of schemes that aim to maximize the purity and…

[Phys. Rev. A 92, 053849] Published Fri Nov 20, 2015

]]>We examine the evolution of a time-varying perturbation signal pumped into a monomode fiber in the anomalous dispersion regime. We establish analytically that the perturbation evolves into a conservative pattern of periodic pulses whose structures and profiles share a close similarity with the so-ca…

[Phys. Rev. A 92, 053850] Published Fri Nov 20, 2015

]]>We develop a rigorous connection between statistical properties of an interference pattern and the coherence properties of the underlying quantum state. With explicit examples, we demonstrate that even for inaccurate reconstructions of interference patterns, properly defined statistical moments perm…

[Phys. Rev. A 92, 052114] Published Thu Nov 19, 2015

]]>Quantum systems can be used to certify the existence of true randomness in nature, and semi-device-independent (SDI) randomness expansion has been used to achieve this goal under the prepare-measure configuration. Usually, randomness is certified with the degree of violation of some inequalities. Ho…

[Phys. Rev. A 92, 052321] Published Thu Nov 19, 2015

]]>In engineered quantum systems, the Hamiltonian is often not completely known and needs to be determined experimentally with accuracy and efficiency. We show that this may be done at temperatures that are higher than the characteristic interaction energies, but not too much higher. The condition for …

[Phys. Rev. A 92, 052322] Published Thu Nov 19, 2015

]]>We argue that a quantum annealer at very long annealing times is likely to experience a quasistatic evolution, returning a final population that is close to a Boltzmann distribution of the Hamiltonian at a single (freeze-out) point during the annealing. Such a system is expected to correlate with cl…

[Phys. Rev. A 92, 052323] Published Thu Nov 19, 2015

]]>We present a detailed analysis of the Bell measurement scheme proposed in Lee *et al.* [Phys. Rev. Lett. **114**, 113603 (2015)] based on a logical qubit using Greenberger-Horne-Zeilinger entanglement of photons. The success probability of the proposed Bell measurement can be made arbitrarily high using o…

[Phys. Rev. A 92, 052324] Published Thu Nov 19, 2015

]]>We present a realistic molecular-dynamics treatment of laser-cooled ions in radio-frequency ion traps which avoids previously made simplifications such as modeling laser cooling as a friction force and combining individual heating mechanisms into a single effective heating force. Based on this imple…

[Phys. Rev. A 92, 053420] Published Thu Nov 19, 2015

]]>We report on an atom interferometer based on Bragg diffraction in a fountain of alkaline-earth-metal atoms, namely ${}^{88}\mathrm{Sr}$. We demonstrate large momentum transfer to the atoms up to eight photon recoils and the use of the interferometer as a gravimeter with a sensitivity $\delta g/g=4\times {10}^{-8}$. Thanks to the spec…

[Phys. Rev. A 92, 053619] Published Thu Nov 19, 2015

]]>We investigate radio-frequency (rf) spectroscopy, metal-to-superconductor tunneling, and angle-resolved photoemission spectroscopy (ARPES) as probes of isolated out-of-equilibrium quantum systems, and examine the crucial role played by the nonequilibrium distribution function. As an example, we focu…

[Phys. Rev. A 92, 053620] Published Thu Nov 19, 2015

]]>The existence of multidimensional lattice compactons in the discrete nonlinear Schrödinger equation in the presence of fast periodic time modulations of the nonlinearity is demonstrated. By averaging over the period of the fast modulations, an effective averaged dynamical equation arises with coupli…

[Phys. Rev. A 92, 053621] Published Thu Nov 19, 2015

]]>A system of ${N}_{a}$ atoms of $n$ levels interacting dipolarly with $\ell $ modes of an electromagnetic field is considered. The energy surface of the system is constructed from the direct product of the coherent states of $\mathrm{U}\left(n\right)$ in the totally symmetric representation for the matter times the $\ell $ coherent states of …

[Phys. Rev. A 92, 053843] Published Thu Nov 19, 2015

]]>We describe a two-photon quantum interference effect which differs from the Hong-Ou-Mandel effect in that the destructive quantum inference occurs on a component of the state where two photons are in a single output mode while maintaining the two-photon events in the alternative mode. This effect is…

[Phys. Rev. A 92, 053844] Published Thu Nov 19, 2015

]]>We derive analytic expressions for the on-resonant cavity scale factor enhancement dependence on temperature, ${S}_{0}\left(T\right)$, for an intracavity medium with a Gaussian absorption resonance. Results are expressed as functions of the cavity parameters and the two resonance parameters: ${\alpha}_{0}\left(T\right)$, the peak absorptio…

[Phys. Rev. A 92, 053845] Published Thu Nov 19, 2015

]]>Coupling light to Rydberg states of atoms under conditions of electromagnetically induced transparency (EIT) leads to the formation of interacting quasiparticles, termed Rydberg polaritons. We derive a one-dimensional model describing the time evolution of these polaritons under paraxial propagation…

[Phys. Rev. A 92, 053846] Published Thu Nov 19, 2015

]]>The theoretical description of dynamics in open quantum systems becomes very demanding upon inclusion of non-Markovian effects. To simplify the computational implementation for density matrix equations of motion, the secular approximation is often applied. An experimental verification of its validit…

[Phys. Rev. A 92, 052113] Published Wed Nov 18, 2015

]]>In this work, a quantum error correction (QEC) procedure with the concatenated five-qubit code is used to construct a near-perfect effective qubit channel (with a error below ${10}^{-5}$) from arbitrary noise channels. The exact performance of the QEC is characterized by a Choi matrix, which can be obtaine…

[Phys. Rev. A 92, 052320] Published Wed Nov 18, 2015

]]>We report on the measurement of double-differential distribution of soft electron emission from ${\text{C}}_{60}$ fullerene, induced by a fast-moving Coulomb field of 76 MeV energy bare fluorine ions. A broad “plasmon-electron” peak, riding on the Coulomb-ionization continuum, is observed due to the deexcitation …

[Phys. Rev. A 92, 052708] Published Wed Nov 18, 2015

]]>We present a comprehensive study of the discretized modes of an atomic gas in different conditions of confinement. Starting from the equations of hydrodynamics we derive a closed equation for the velocity field, depending on the adiabatic and isothermal compressibilities and applicable to different …

[Phys. Rev. A 92, 053617] Published Wed Nov 18, 2015

]]>A discrepancy between existing theories and essentially exact numerical results on the asymmetry of the mobility edge for Anderson localization is now resolved, where an improved single-particle Green’s function — a crucial component that could be used in existing theories for other relevant studies — is found to bridge the gap.

[Phys. Rev. A 92, 053618] Published Wed Nov 18, 2015

]]>Quantum optics in combination with integrated optical devices shows great promise for efficient manipulation of single photons. New physical concepts, however, can only be found when these fields truly merge and reciprocally enhance each other. Here we work at the merging point and investigate the p…

[Phys. Rev. A 92, 053841] Published Wed Nov 18, 2015

]]>A breakdown of the hyperfine coupling in a deep optical-dipole trap is observed for single ${}^{87}$Rb atoms, an effect which has implications for future experiments with atomic clocks, in quantum information processing, and quantum many-body physics.

[Phys. Rev. A 92, 053842] Published Wed Nov 18, 2015

]]>A quantum system subjected to a strong continuous monitoring undergoes quantum jumps. This very-well-known fact hides a neglected subtlety: sharp scale-invariant fluctuations invariably decorate the jump process, even in the limit where the measurement rate is very large. This article is devoted to …

[Phys. Rev. A 92, 052111] Published Tue Nov 17, 2015

]]>The thermometry precision of a sample is a question of both fundamental and technological importance. In this paper, we consider a ring-structure system as our probe to estimate the temperature of a bath. Based on the Markovian master equation of the probe, we calculate the quantum Fisher informatio…

[Phys. Rev. A 92, 052112] Published Tue Nov 17, 2015

]]>It was recently shown by Motes, Gilchrist, Dowling, and Rohde [Phys. Rev. Lett. **113**, 120501 (2014)] that a time-bin encoded fiber-loop architecture can implement an arbitrary passive linear optics transformation. This was shown in the case of an ideal scheme whereby the architecture has no sources o…

[Phys. Rev. A 92, 052319] Published Tue Nov 17, 2015

]]>The dynamical evolution of spatial patterns in a complex system can reveal the underlying structure and stability of stationary states. As a model system we employ a two-component Bose-Einstein condensate at the transition from miscible to immiscible with the additional control of linear interconver…

[Phys. Rev. A 92, 053614] Published Tue Nov 17, 2015

]]>We discuss the effects of quantum and thermal fluctuations on the Majorana edge states in a topological atomic wire coupled to a superfluid molecular gas with gapless excitations. We find that the coupling between the Majorana edge states remains exponentially decaying with the length of the wire, e…

[Phys. Rev. A 92, 053615] Published Tue Nov 17, 2015

]]>We explore the superfluid phases of a two-component Fermi mixture with hybridized orbitals in optical lattices. We show that there exists a general mapping of this system to the Lieb lattice. By using simple multiband models with hopping between $s$- and $p$-orbital states, we show that superfluid order…

[Phys. Rev. A 92, 053616] Published Tue Nov 17, 2015

]]>We investigate the formation of a localized plateau beam in the transverse section of a nonlinear optical ring cavity filled with a metamaterial and a nonlocal medium such as a nematic liquid crystal. We show that, far from the modulational instability regime, localized structures with a varying wid…

[Phys. Rev. A 92, 053838] Published Tue Nov 17, 2015

]]>We derive and validate a set of coupled Bloch wave equations for analyzing the reflection and transmission properties of active semiconductor photonic-crystal waveguides. In such devices, slow-light propagation can be used to enhance the material gain per unit length, enabling, for example, the real…

[Phys. Rev. A 92, 053839] Published Tue Nov 17, 2015

]]>Absorption spectrum of a system of two closely spaced identical atoms displays, at certain preparation, a dip that can be much narrower than the natural linewidth. This preparation includes (i) application of a strong magnetic field at an angle $\alpha $, that is very close to the magic angle ${\alpha}_{0}=arccos(1/\sqrt{3})\dots $

[Phys. Rev. A 92, 053840] Published Tue Nov 17, 2015

]]>A recent study of soft x-ray absorption in native and hydrogenated coronene cations, ${\mathrm{C}}_{24}{{\mathrm{H}}_{12+m}}^{+}\phantom{\rule{4pt}{0ex}}m=0\u20137$, led to the conclusion that additional hydrogen atoms protect (interstellar) polycyclic aromatic hydrocarbon (PAH) molecules from fragmentation [Reitsma *et al.*, Phys. Rev. Lett. **113**, 053002 (2014)]. …

[Phys. Rev. A 92, 050702(R)] Published Mon Nov 16, 2015

]]>The dynamics of an open quantum system is often modeled by introducing a bath initially in a product state with the system, letting the system and bath evolve unitarily together, and then tracing over the bath. However, often this model may not accurately reflect a particular experimental situation.…

[Phys. Rev. A 92, 052110] Published Mon Nov 16, 2015

]]>We show how weak nonlinearities can be used in a device-independent quantum key distribution (QKD) protocol using generalized two-mode Schrödinger cat states. The QKD protocol is therefore shown to be secure against collective attacks and for some coherent attacks. We derive analytical formulas for …

[Phys. Rev. A 92, 052318] Published Mon Nov 16, 2015

]]>We report a combined experimental and theoretical study on the electron-impact ionization of helium at ${E}_{0}\phantom{\rule{0.28em}{0ex}}=\phantom{\rule{0.28em}{0ex}}70.6\phantom{\rule{0.28em}{0ex}}\mathrm{eV}$ and equal energy sharing of the two outgoing electrons (${E}_{1}={E}_{2}=23\phantom{\rule{0.28em}{0ex}}\mathrm{eV}$), where a double-peak or dip structure in the binary region of the triple differential cross section is observed. The ex…

[Phys. Rev. A 92, 052707] Published Mon Nov 16, 2015

]]>In the vicinity of a Feshbach resonance, a system of ultracold atoms in an optical lattice undergoes rich physical transformations which involve molecule formation and hopping of molecules on the lattice and thus goes beyond a single-band Hubbard model description. We explore theoretically the respo…

[Phys. Rev. A 92, 053612] Published Mon Nov 16, 2015

]]>We investigated the Raman-pulse-duration effect in a gravity gradiometer with two atom interferometers. Since the two atom clouds in the gradiometer experience different gravitational fields, it is hard to compensate for the Doppler shifts of the two clouds simultaneously by chirping the frequency o…

[Phys. Rev. A 92, 053613] Published Mon Nov 16, 2015

]]>We study the time-resolved dynamics of high-order harmonic generation (HHG) from oriented asymmetric molecules in intense laser fields theoretically. Previous studies have shown that the odd-even HHG spectra of asymmetric molecules don't show the striking two-center-interference-induced minimum, as …

[Phys. Rev. A 92, 053833] Published Mon Nov 16, 2015

]]>The analysis of photon scattering is a major challenge in the multiphoton regime. A framework based on a path-integral formalism provides a route to explore such dynamics, helping to investigate the quantum statistics of photons interacting with complex structures.

[Phys. Rev. A 92, 053834] Published Mon Nov 16, 2015

]]>Phase-sensitive properties of light play a crucial role in a variety of quantum optical phenomena, which have been mostly discussed in the framework of photoelectric detection theory. However, modern detection schemes, such as arrays of on-off detectors, are not based on photoelectric counting. We d…

[Phys. Rev. A 92, 053835] Published Mon Nov 16, 2015

]]>Analytic expressions for the electric and magnetic fields of a radially polarized ultrashort and tightly focused laser pulse, propagating in vacuum, are derived from scalar and vector potentials satisfying simple initial conditions. It is shown that for a pulse of axial length comparable to a wavele…

[Phys. Rev. A 92, 053836] Published Mon Nov 16, 2015

]]>Recent demonstrations of parity-time- $(\mathcal{PT}$-) symmetric structure have exhibited the great potential of this system for tailoring the light-matter interaction and developing a wide range of robust quantum devices. Here we explore the second-order photon correlations in a $\mathcal{PT}$-symmetric system consisting…

[Phys. Rev. A 92, 053837] Published Mon Nov 16, 2015

]]>The problems of optimizing the value of an arbitrary observable of a two-level system at both a fixed time and the shortest possible time is theoretically explored. Complete identification and classification along with comprehensive analysis of globally optimal control policies and traps (i.e., poli…

[Phys. Rev. A 92, 052109] Published Fri Nov 13, 2015

]]>Within the broad research scenario of quantum secure communication, two-way quantum key distribution (TWQKD) is a relatively new proposal for sharing secret keys that is not yet fully explored. We analyze the security of TWQKD schemes that use qubits prepared in nonorthogonal states to transmit the …

[Phys. Rev. A 92, 052317] Published Fri Nov 13, 2015

]]>We model sympathetic cooling of ground-state CaF molecules by ultracold Li and Rb atoms. The molecules are moving in a microwave trap, while the atoms are trapped magnetically. We calculate the differential elastic cross sections for CaF-Li and CaF-Rb collisions, using model Lennard-Jones potentials…

[Phys. Rev. A 92, 053419] Published Fri Nov 13, 2015

]]>Motivated by recent experiments on two-component systems, we investigate the ground-state phase diagram of a mixture of two bosonic species by means of path-integral quantum Monte Carlo simulations by a two-worm algorithm. The mixture is trapped in a square lattice at different filling conditions. V…

[Phys. Rev. A 92, 053610] Published Fri Nov 13, 2015

]]>We present a general method for the high-temperature expansion of the self-energy of interacting particles. Although the method is valid for fermions and bosons, we illustrate it for spin-one-half fermions interacting via a zero range potential, in the Bose-Einstein-condensate–Bardeen-Cooper-Schrief…

[Phys. Rev. A 92, 053611] Published Fri Nov 13, 2015

]]>By using perturbation theory, we show that a hydrogen atom with magnetic moment due to the orbital angular momentum of the electron has so-called hidden momentum in the presence of an external electric field. This means that the atomic electronic cloud has a nonzero linear momentum in its center-of-…

[Phys. Rev. A 92, 052107] Published Thu Nov 12, 2015

]]>The adiabatic Aharonov-Bohm (AB) effect is a manifestation of the Berry phase acquired when some slow variables take a planar spin around a loop. While the effect has been observed in molecular spectroscopy, direct measurement of the topological phase shift in a scattering experiment has been elusiv…

[Phys. Rev. A 92, 052108] Published Thu Nov 12, 2015

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