We investigate the dissipative influence of environmental fluctuations on the dynamics of driven quantum systems at an avoided crossing. We derive two simple approximative equations valid for weak system-bath coupling and compare results for the dissipative Landau-Zener problem with numerically exac...

[Phys. Rev. A 90, 042112] Published Mon Oct 20, 2014

]]>Heisenberg's uncertainty principle is quantified by error-disturbance tradeoff relations, which have been tested experimentally in various scenarios. Here we shall report various error-disturbance tradeoff relations by decomposing the measurement errors and disturbance into two different components,...

[Phys. Rev. A 90, 042113] Published Mon Oct 20, 2014

]]>We propose a method for deterministic generation of entanglement between a quantum-dot spin and a photon. Entanglement is established by an elastic scattering event from a cavity that is strongly coupled to a singly charged quantum dot. Due to the elastic nature of the interaction, the energy of the...

[Phys. Rev. A 90, 042322] Published Mon Oct 20, 2014

]]>We study the H3×N hybrid entanglement between charge and vibrational modes in a triple-quantum-dot shuttle system. Three quantum dots are linearly connected, with the outer dots fixed and the central dot oscillating, described as a quantum harmonic oscillator with oscillation modes that are entangle...

[Phys. Rev. A 90, 042323] Published Mon Oct 20, 2014

]]>We consider systems of two and three qubits, mutually coupled by Heisenberg-type exchange interaction and interacting with external laser fields. We show that these systems allow one to create maximally entangled Bell states, as well as three-qubit Greenberger-Horne-Zeilinger and W states. In partic...

[Phys. Rev. A 90, 042324] Published Mon Oct 20, 2014

]]>A theoretical model of the influence of detection bandwidth properties on observed line shapes in laser absorption spectroscopy is described, thereby predicting artificial frequency shifts, extra broadenings, and line asymmetries which must be taken into account in order to obtain accurate line parameters.

[Phys. Rev. A 90, 042506] Published Mon Oct 20, 2014

]]>We develop a theoretical framework for the quasi-low-dimensional confinement-induced resonances (CIRs) of particles with three-dimensional two-body interactions describable by the Huang-Yang pseudopotential. Using this approach, we analytically obtain the universal properties of dipolar CIRs in quas...

[Phys. Rev. A 90, 042710] Published Mon Oct 20, 2014

]]>We show that Jaynes-Cummings dynamics can be observed in mesoscopic atomic ensembles interacting with a classical electromagnetic field in the regime of a Rydberg blockade where the time dynamics of the average number of Rydberg excitations in mesoscopic ensembles displays collapses and revivals typ...

[Phys. Rev. A 90, 043413] Published Mon Oct 20, 2014

]]>We study a spin-orbit (SO)-coupled hyperfine spin-1 Bose-Einstein condensate (BEC) in a quasi-one-dimensional trap. For an SO-coupled BEC in a one-dimensional box, we show that in the absence of the Rabi term, any nonzero value of SO coupling will result in a phase separation among the components fo...

[Phys. Rev. A 90, 043619] Published Mon Oct 20, 2014

]]>A two-dimensional Bose-Einstein condensate (BEC) split by a radial potential barrier is investigated. We determine on an accurate many-body level the system's ground-state phase diagram as well as a time-dependent phase diagram of the splitting process. Whereas the ground state is condensed for a wi...

[Phys. Rev. A 90, 043620] Published Mon Oct 20, 2014

]]>The collective excitations of a zero-temperature, spin-polarized, harmonically trapped, two-dimensional dipolar Fermi gas are examined within the Thomas-Fermi–von Weizsäcker hydrodynamic theory. We focus on repulsive interactions and investigate the dependence of the excitation frequencies on the st...

[Phys. Rev. A 90, 043621] Published Mon Oct 20, 2014

]]>A light-matter interaction modified by the material environment is one of the central topics in quantum electrodynamics. While a strong coupling between a single emitter and a cavity and the Markovian (exponential) relaxation regime are most straightforwardly covered by theory, real physical systems...

[Phys. Rev. A 90, 043836] Published Mon Oct 20, 2014

]]>We show how interference effects are responsible for manipulating the output electromagnetic field of an optical microresonator in the good-cavity limit. The system of interest consists of a moderately strongly pumped two-level emitter embedded in the optical cavity. When an additional weaker laser ...

[Phys. Rev. A 90, 043837] Published Mon Oct 20, 2014

]]>The resonant quantum dynamics of an excited two-level emitter is investigated via classical modulation of its transition frequency while simultaneously the radiator interacts with a broadband electromagnetic field reservoir. The frequency of modulation is selected to be of the order of the bare-stat...

[Phys. Rev. A 90, 043838] Published Mon Oct 20, 2014

]]>We propose a scheme to efficiently manipulate optomechanical systems into and out of chaotic regimes. Here the optical system is coherently driven by a continuous-wave bichromatic laser field consisting of a pump field and a probe field, where the beat frequency of the bichromatic components plays a...

[Phys. Rev. A 90, 043839] Published Mon Oct 20, 2014

]]>Quantum optomechanics offers the potential to investigate quantum effects in macroscopic quantum systems in extremely well-controlled experiments. In this paper we discuss one such situation, the dynamic stabilization of a mechanical system such as an inverted pendulum. The specific example that we ...

[Phys. Rev. A 90, 043840] Published Mon Oct 20, 2014

]]>One-way quantum computing uses single-qubit projective measurements performed on a cluster state (a highly entangled state of multiple qubits) in order to enact quantum gates. The model is promising due to its potential scalability; the cluster state may be produced at the beginning of the computati...

[Phys. Rev. A 90, 043841] Published Mon Oct 20, 2014

]]>Quantum spin chains may be used to transfer quantum states between elements of a quantum information processing device. A scheme discovered recently [Phys. Rev. A 85, 022312 (2012)PLRAAN10.1103/PhysRevA.85.022312] was shown to have favorable transfer properties for single-qubit states even in the pr...

[Phys. Rev. A 90, 044301] Published Mon Oct 20, 2014

]]>Spontaneous parametric down-conversion (SPDC) in a nonlinear crystal generates two single photons (signal and idler) with random phases. Thus, no first-order interference between them occurs. However, coherence can be induced in a cascaded setup of two crystals if, e.g., the idler modes of both crys...

[Phys. Rev. A 90, 045803] Published Mon Oct 20, 2014

]]>We contribute to a long-standing debate on the supposed failure of the fluctuation dissipation theorem (FDT) for the Davies master equation (DME), an important class of Lindblad quantum master equations, describing time-driven quantum systems weakly coupled to a heat bath. First we propose two simpl...

[Phys. Rev. A 90, 042110] Published Fri Oct 17, 2014

]]>We study the (2 + 1)-dimensional Dirac oscillator in a homogeneous magnetic field in the noncommutative plane. It is shown that the effect of noncommutativity is twofold: (i) momentum noncommuting coordinates simply shift the critical value (Bcr) of the magnetic field at which the well known left-ri...

[Phys. Rev. A 90, 042111] Published Fri Oct 17, 2014

]]>We study the x-ray emission following the collision of a Bi83+ ion with a neutral Xe atom at the projectile energy 70 MeV/u. The collisional and post-collisional processes are treated separately. The probabilities of various many-electron processes at the collision are calculated within a relativist...

[Phys. Rev. A 90, 042709] Published Fri Oct 17, 2014

]]>We present measurements of resistive and sympathetic cooling of ion clouds confined in a Penning trap. For resistive cooling of a cloud consisting of one ion species, we observe a significant deviation from exponential cooling behavior which is explained by an energy-transfer model. The observed sym...

[Phys. Rev. A 90, 043412] Published Fri Oct 17, 2014

]]>We study the evolution of correlations in a quasi-two-dimensional dipolar gas driven out of equilibrium by a sudden ramp of the interactions. On short time scales, rotonlike excitations coherently oscillate in and out of the condensate, giving rise to pronounced features in the time evolution of the...

[Phys. Rev. A 90, 043617] Published Fri Oct 17, 2014

]]>With the aid of numerical simulations, the phase diagram of ultracold bosonic atoms in optical lattices can be reconstructed using a quantum nondemolition measurements based on the quantum Faraday effect.

[Phys. Rev. A 90, 043618] Published Fri Oct 17, 2014

]]>On the basis of the Maxwell-Lorentz local-field equations and nonlocal linear response theory, a self-consistent microscopic Green function theory of diffraction of light from a single hole in a thin and plane metallic screen is established. By subtracting the scattering of identical incident fields...

[Phys. Rev. A 90, 043830] Published Fri Oct 17, 2014

]]>We consider how a single photon can probe the quantum nature of a moving mirror in the context of quantum optomechanics. In particular, we demonstrate how the single-photon time-dependent spectrum reveals the time required for the fully resolved spectrum to build up as a result of the single photon ...

[Phys. Rev. A 90, 043831] Published Fri Oct 17, 2014

]]>We employ a quasimode representation of the adjoint master equation to study nonlinear pair-generation dynamics via spontaneous four-wave mixing in coupled-cavity systems in the presence of scattering loss. Perturbative analytic solutions for signal and idler photon-number operators are derived, whi...

[Phys. Rev. A 90, 043832] Published Fri Oct 17, 2014

]]>We study mode properties in multimode optical waveguides with parity-time (PT) symmetry. We find that two guiding modes with successive orders 2m−1 and 2m form a mode pair in the sense that the two components of the pair evolve into the same mode when the loss and gain coefficient increases to some ...

[Phys. Rev. A 90, 043833] Published Fri Oct 17, 2014

]]>In this paper we investigate the propagation of an intense linearly polarized laser through an ionizing gaseous medium in the presence of an axial strong magnetic field, addressing the modulation of laser polarization. Our simulation indicates that the laser polarization can be dramatically modulate...

[Phys. Rev. A 90, 043834] Published Fri Oct 17, 2014

]]>We demonstrate the stabilization of an unstable steady state in an optomechanical system for low and high pump rates. The optomechanical system consists of a pumped cavity with one movable mirror. The stabilization is achieved by applying Pyragas control, i.e., feeding back the cavity field by an ex...

[Phys. Rev. A 90, 043835] Published Fri Oct 17, 2014

]]>We derive a general approximate solution to the problem of minimizing the conditional entropy of a qudit-qubit system resulting from a local measurement on the qubit, which is valid for general entropic forms and becomes exact in the limit of weak correlations. This entropy measures the average cond...

[Phys. Rev. A 90, 042318] Published Thu Oct 16, 2014

]]>Quantum technology promises revolutionary advantages in information processing and transmission compared to classical technology; however, determining which specific resources are needed to surpass the capabilities of classical machines often remains a nontrivial problem. To address such a problem, ...

[Phys. Rev. A 90, 042319] Published Thu Oct 16, 2014

]]>For any N⊗N-type bipartite system with even N>2, two-parameter continuous families of unital block-dephasing quantum channels and of weakly optimal entanglement witnesses are constructed from special forms of a parametrized positive map. The parameter domains of the families are complementary sub...

[Phys. Rev. A 90, 042320] Published Thu Oct 16, 2014

]]>Adiabatic quantum computation, based on the adiabatic theorem, is a promising alternative to conventional quantum computation. The validity of an adiabatic algorithm depends on the existence of a nonzero energy gap between the ground and excited states. However, it is difficult to ascertain the exac...

[Phys. Rev. A 90, 042321] Published Thu Oct 16, 2014

]]>We present electronic stopping power data for H and He ions in Zn and In obtained from backscattering experiments in the range of low velocities; for In data are obtained up to the stopping maximum. These results in combination with previous data are analyzed to unravel the influence of d electrons ...

[Phys. Rev. A 90, 042706] Published Thu Oct 16, 2014

]]>We explore the three-body problem in two dimensions using the adiabatic hyperspherical representation. We develop the main equations in terms of democratic hyperangular coordinates and determine several symmetry properties and boundary conditions for both interacting and noninteracting solutions. Fr...

[Phys. Rev. A 90, 042707] Published Thu Oct 16, 2014

]]>Stationary afterglow measurements in conjunction with near-infrared absorption spectroscopy show that the recombination of the H3+ ion with electrons in ionized gas mixtures of He, Ar, and H2 at 300 K is strongly enhanced by neutral helium and by molecular hydrogen. The H2-assisted ternary recombina...

[Phys. Rev. A 90, 042708] Published Thu Oct 16, 2014

]]>We predict the effect of the roton instability for a two-dimensional weakly interacting gas of tilted dipoles in a single homogeneous quantum layer. Being typical for strongly correlated systems, the roton phenomena appear to occur in a weakly interacting gas. It is important that in contrast to a s...

[Phys. Rev. A 90, 043616] Published Thu Oct 16, 2014

]]>We present a microscopic model of cavity quantum electrodynamics based on a one-dimensional (1D) coupled cavity array (CCA), where a supercavity (SC) is composed by a segment of the 1D CCA with relatively smaller couplings with the outsides. The single-photon scattering problem for the SC empty or w...

[Phys. Rev. A 90, 043828] Published Thu Oct 16, 2014

]]>Conservation of spin angular momentum in high-harmonic generation is probed using bichromatic counter-rotating high-intensity laser pulses.

[Phys. Rev. A 90, 043829] Published Thu Oct 16, 2014

]]>A method to dynamically decouple the effects of two-body atom-atom interactions for ultracold bosonic atoms and realize a system dominated by three-body interactions is presented, which is useful for a number of applications such as the possible realization of novel three-body phases and states.

[Phys. Rev. A 90, 041602] Published Wed Oct 15, 2014

]]>Adiabatic transport provides a powerful way to manipulate quantum states. By preparing a system in a readily initialized state and then slowly changing its Hamiltonian, one may achieve quantum states that would otherwise be inaccessible. Moreover, a judicious choice of final Hamiltonian whose ground...

[Phys. Rev. A 90, 042317] Published Wed Oct 15, 2014

]]>Motivated by the remarkable experimental control of synthetic gauge fields in ultracold atomic systems, we investigate the effect of an artificial Rashba spin-orbit coupling on the spin polarization of a two-dimensional repulsive Fermi gas. By using a variational many-body wave function, based on a ...

[Phys. Rev. A 90, 043614] Published Wed Oct 15, 2014

]]>Expressions for the speed and lifetimes of the sound modes in a dilute Bose-Einstein condensate are obtained using Bogoliubov mean field theory. The condensate has two pairs of sound modes which undergo an avoided crossing as the equilibrium temperature is varied. The two pairs of sound modes decay ...

[Phys. Rev. A 90, 043615] Published Wed Oct 15, 2014

]]>We study the far-from-equilibrium statistical mechanics of periodically driven fermionic atoms in a lossy optical resonator. We show that the interplay of the Fermi surface with cavity losses leads to subnatural cavity linewidth narrowing, squeezed light, and nonthermal quantum statistics of the ato...

[Phys. Rev. A 90, 043823] Published Wed Oct 15, 2014

]]>We study an atom-cavity system composed of an ensemble of three-level atoms interacting with a high-finesse single-mode optical resonator. Two examples of physical models, the laser-driven Λ-type atomic system and the three-level ladder-type atomic system, are investigated in detail. By altering the...

[Phys. Rev. A 90, 043824] Published Wed Oct 15, 2014

]]>We study the dynamics of a driven optomechanical cavity coupled to a charged nanomechanical resonator via Coulomb interaction, in which the tunable double optomechanically induced transparency (OMIT) can be observed from the output field at the probe frequency by controlling the strength of the Coul...

[Phys. Rev. A 90, 043825] Published Wed Oct 15, 2014

]]>We capitalize on a multipolar expansion of the polarization density matrix, in which multipoles appear as successive moments of the Stokes variables. When all the multipoles up to a given order K vanish, we can properly say that the state is Kth-order unpolarized, as it lacks of polarization informa...

[Phys. Rev. A 90, 043826] Published Wed Oct 15, 2014

]]>The Talbot effect, i.e., the self-imaging property of a periodic wave in near-field diffraction, is a remarkable interference phenomenon in paraxial systems with continuous translational invariance. In crystals, i.e., systems with discrete translational invariance, self-imaging has been regarded so ...

[Phys. Rev. A 90, 043827] Published Wed Oct 15, 2014

]]>[Phys. Rev. A 90, 049902] Published Wed Oct 15, 2014

]]>The performance of a quantum information processor depends on the precise control of phases introduced into the system during quantum gate operations. As the number of operations increases with the complexity of a computation, the phases of the gates at different locations and different times must b...

[Phys. Rev. A 90, 042316] Published Tue Oct 14, 2014

]]>We study a wide range of neutral atoms and ions suitable for ultraprecise atomic optical clocks with naturally suppressed blackbody-radiation shift of clock transition frequency. Calculations show that scalar polarizabilities of clock states cancel each other for at least one order of magnitude for ...

[Phys. Rev. A 90, 042505] Published Tue Oct 14, 2014

]]>High-order-harmonic generation is investigated for H2+ and D2+ with and without a Born-Oppenheimer approximation by a numerical solution of a full dimensional electronic time-dependent Schrödinger equation under four-cycle intense laser pulses of 800 nm wavelength and I=4, 5, 7, and 10×1014 W/cm2 in...

[Phys. Rev. A 90, 043411] Published Tue Oct 14, 2014

]]>A simple model of parametric coupling between two fermionic oscillators is considered. Statistical properties, in particular the mean and variance of quanta for a single mode, are described by means of a time-dependent reduced density operator for the system and the associated P function. The densit...

[Phys. Rev. A 90, 043820] Published Tue Oct 14, 2014

]]>In recent studies [Liew et al., Phys. Rev. Lett. 104, 183601 (2010)PRLTAO10.1103/PhysRevLett.104.183601; Bamba et al., Phys. Rev. A 83, 021802(R) (2011)PLRAAN10.1103/PhysRevA.83.021802], due to destructive interference between different paths for two-photon excitation, strong photon antibunching can...

[Phys. Rev. A 90, 043822] Published Tue Oct 14, 2014

]]>The standard PT-symmetric dimer is a linearly coupled two-site discrete nonlinear Schrödinger equation with one site losing and the other one gaining energy at the same rate. We show that despite gain and loss, the standard PT dimer is a Hamiltonian system. We also produce a Lagrangian formulation f...

[Phys. Rev. A 90, 045802] Published Tue Oct 14, 2014

]]>Although interference is a classical-wave phenomenon, the superposition principle, which underlies interference of individual particles, is at the heart of quantum physics. An interaction-free measurement (IFM) harnesses the wave-particle duality of single photons to sense the presence of an object ...

[Phys. Rev. A 90, 042109] Published Mon Oct 13, 2014

]]>The problem of deducing the global properties of correlations of tripartite quantum states based on the knowledge of their bipartite reductions is studied, shedding new light on the relation between local and global properties of quantum states and on the interplay between the classical and the quantum properties of correlations.

[Phys. Rev. A 90, 042314] Published Mon Oct 13, 2014

]]>The surface code is a promising alternative for implementing fault-tolerant, large-scale quantum information processing. Its high threshold for single-qubit errors under stochastic noise is one of its most attractive features. We develop an exact formulation for the fidelity of the surface code that...

[Phys. Rev. A 90, 042315] Published Mon Oct 13, 2014

]]>We report on experimental and theoretical investigations of dynamic evolution of individual R-branch laser lines from tunnel-ionized nitrogen molecules based on a pump-probe scheme. Our observation shows that the intensities of the R-branch laser lines exhibit rapid oscillations which can be decompo...

[Phys. Rev. A 90, 042504] Published Mon Oct 13, 2014

]]>A modified empirical ionization formula is proposed to extend Tong and Lin's ionization formula [X. M. Tong and C. D. Lin, J. Phys. B 38, 2593 (2005)JPAPEH10.1088/0953-4075/38/15/001] to a laser field up to 4.5 times barrier-suppression strength (Eb) in the over-barrier regime. The validity of the f...

[Phys. Rev. A 90, 043410] Published Mon Oct 13, 2014

]]>We study steady-state evaporation in an atom guide via Monte Carlo simulations. The evaporation surface follows a specific profile as a function of longitudinal guide location. We demonstrate that the choice of evaporation profile significantly impacts the performance of the evaporation. Our simulat...

[Phys. Rev. A 90, 043612] Published Mon Oct 13, 2014

]]>We study the stroboscopic and nonstroboscopic dynamics in the Floquet realization of the Harper-Hofstadter Hamiltonian. We show that the former produces the evolution expected in the high-frequency limit only for observables, which commute with the operator to which the driving protocol couples. On ...

[Phys. Rev. A 90, 043613] Published Mon Oct 13, 2014

]]>Optical analogies of macroscopic quantum effects (Schrödinger cat states, squeezing, collapse, and revival) for light beams propagating in an inhomogeneous linear medium are demonstrated theoretically using exact analytical solutions of the wave equation. It is shown that the coherent superposition ...

[Phys. Rev. A 90, 043814] Published Mon Oct 13, 2014

]]>We show the emergence of light localization in arrays of coupled optical waveguides with randomness only in the imaginary part of their refractive index and develop a one-parameter scaling theory for the normalized participation number of Floquet-Bloch modes. This localization introduces a different...

[Phys. Rev. A 90, 043815] Published Mon Oct 13, 2014

]]>We describe and analyze a quasi-phase-matching scheme for nonlinear optical frequency conversion where the spatial modulation of mode intensity in coupled parallel waveguides provides the required modulation in the generation of the frequency conversion signal, instead of a variation of any material...

[Phys. Rev. A 90, 043816] Published Mon Oct 13, 2014

]]>The ultrastrong-coupling regime, where the atom-cavity coupling rate reaches a considerable fraction of the cavity or atom transition frequencies, has been reported in a flux qubit superconducting quantum circuit coupled to an on-chip coplanar resonator. In this regime situations may arise where the...

[Phys. Rev. A 90, 043817] Published Mon Oct 13, 2014

]]>Precise measurement is crucial to science and technology. However, the rule of nature imposes various restrictions on the precision that can be achieved depending on specific methods of measurement. In particular, quantum mechanics poses the ultimate limit on precision which can only be approached b...

[Phys. Rev. A 90, 043818] Published Mon Oct 13, 2014

]]>We investigate a type of matched infrared soliton pairs based on four-wave mixng (FWM) in Landau-quantized graphene by using density-matrix method and perturbation theory. The linear and nonlinear dynamical properties of the graphene system are first discussed, and, in particular, we focus on the si...

[Phys. Rev. A 90, 043819] Published Mon Oct 13, 2014

]]>We investigate the effects of a time-periodic, non-Hermitian, PT-symmetric perturbation on a system with two (or few) levels, and obtain its phase diagram as a function of the perturbation strength and frequency. We prove that when the perturbation frequency is close to one of the system resonances,...

[Phys. Rev. A 90, 040101] Published Fri Oct 10, 2014

]]>Time-resolved photon detection can be used to generate entanglement between distinguishable photons. This technique can be extended to entangle quantum memories that emit photons with different frequencies and identical temporal profiles without the loss of entanglement rate or fidelity. We experime...

[Phys. Rev. A 90, 040302] Published Fri Oct 10, 2014

]]>Non-Markovian evolution of an open quantum system can be induced by the memory effects of a reservoir. Although a reservoir with stronger memory effects may seem like it should cause stronger non-Markovian effects on the system of interest, this seemingly intuitive thinking may not always be correct...

[Phys. Rev. A 90, 042108] Published Fri Oct 10, 2014

]]>The classical capacity of phase-invariant Gaussian channels has been recently determined under the assumption that such channels are memoryless. In this work we generalize this result by deriving the classical capacity of a model of quantum memory channel, in which the output states depend on the pr...

[Phys. Rev. A 90, 042312] Published Fri Oct 10, 2014

]]>We study the robustness of quantum transport in four-site one-dimensional (1D) particle quantum networks irreversibly connected to a target site in the presence of environmental dephasing noise. Under conditions of Markovian decoherence we define a quantity—which we denote as geometrical robustness—...

[Phys. Rev. A 90, 042313] Published Fri Oct 10, 2014

]]>We present a combined experimental and theoretical study of the fragmentation of HDO2+ molecular ions produced by electron-impact ionization of HDO+ in the collision energy range 20–2500 eV. Experimental absolute partial inclusive cross sections for the production of OD+,OH+, and O+ are reported and...

[Phys. Rev. A 90, 042704] Published Fri Oct 10, 2014

]]>We consider a general problem of inelastic collision of particles interacting with power-law potentials. Using quantum-defect theory we derive an analytical formula for the energy-dependent complex scattering length, valid for arbitrary collision energy, and use it to analyze the elastic and reactiv...

[Phys. Rev. A 90, 042705] Published Fri Oct 10, 2014

]]>The dynamics of Bose-Einstein condensates in asymmetric double wells is studied. We construct a two-mode model and analyze the properties of the corresponding phase-space diagram, showing in particular that the minimum of the phase-space portrait becomes shifted from the origin as a consequence of t...

[Phys. Rev. A 90, 043610] Published Fri Oct 10, 2014

]]>We demonstrate and characterize an experimental technique to directly image the momentum distribution of a strongly interacting two-dimensional quantum gas with high momentum resolution. We apply the principles of Fourier optics to investigate three main operations on the expanding gas: focusing, co...

[Phys. Rev. A 90, 043611] Published Fri Oct 10, 2014

]]>We introduce two types of toroidal metamaterials which are invisible to surface plasmon polaritons (SPPs) propagating on a metal surface. The former is a toroidal handlebody bridging remote holes on the metal surface: It works as a kind of plasmonic counterpart of electromagnetic wormholes. The latt...

[Phys. Rev. A 90, 043812] Published Fri Oct 10, 2014

]]>Tunable optical solitons due to intrapulse stimulated Raman scattering are well known for their ultrashort pulse width, superb pulse quality, and broadband tunability. Consequently they are suitable for a variety of applications, especially multiphoton microscopy (MPM). Recent progress in MPM demand...

[Phys. Rev. A 90, 043813] Published Fri Oct 10, 2014

]]>[Phys. Rev. A 90, 040001] Published Thu Oct 09, 2014

]]>The fact that closed timelike curves (CTCs) are permitted by general relativity raises the question as to how quantum systems behave when time travel to the past occurs. Research into answering this question by utilizing the quantum circuit formalism has given rise to two theories: Deutschian-CTCs (...

[Phys. Rev. A 90, 042107] Published Thu Oct 09, 2014

]]>We present a device-independent quantum cryptography protocol for continuous variables. Our scheme is based on the Gottesman-Kitaev-Preskill encoding scheme whereby a qubit is embedded in the infinite-dimensional space of a quantum harmonic oscillator. The application of discrete-variable device-ind...

[Phys. Rev. A 90, 042311] Published Thu Oct 09, 2014

]]>Measurements of positron scattering off molecules in the vicinity of inelastic-channel threshold energies are reported, showing a strong suppression of the “Wigner cusps” familiar from positron scattering off atomic targets.

[Phys. Rev. A 90, 042703] Published Thu Oct 09, 2014

]]>We investigate the possibility of enhancement of cooling a trapped ion by combining the electromagnetically induced transparency (EIT) effect with the standing-wave coupling. Our study shows that the quantum destructive interference which is caused by the EIT effect and the standing-wave coupling ca...

[Phys. Rev. A 90, 043409] Published Thu Oct 09, 2014

]]>We investigate the thermodynamics of a spin-1 Bose gas with fixed magnetization including the quadratic Zeeman energy shift. Our calculations are based on the grand canonical description for the ideal gas and the classical field approximation for atoms with ferromagnetic and antiferromagnetic intera...

[Phys. Rev. A 90, 043609] Published Thu Oct 09, 2014

]]>Recently [6Phys. Rev. Lett. 106, 093902 (2011)PRLTAO10.1103/PhysRevLett.106.093902] it has been shown that PT-symmetric scattering systems with balanced gain and loss undergo a transition from PT-symmetric scattering eigenstates, which are norm preserving, to symmetry broken pairs of eigenstates exh...

[Phys. Rev. A 90, 043809] Published Thu Oct 09, 2014

]]>A dissipative scheme is proposed to generate single- or two-mode squeezed states in a hybrid quantum system consisting of superconducting resonators and nitrogen-vacancy-center ensembles (NVEs). For the single-mode squeezing generation, we consider an array of linearly coupled superconducting resona...

[Phys. Rev. A 90, 043810] Published Thu Oct 09, 2014

]]>Nonrecolliding tunneling free-state electron wave packets driven by low-frequency ultrashort laser pulses can help synthesize, as we show in this work, extremely short field waveforms lasting a tiny fraction of the field cycle with intensities orders of magnitude higher than the intensities of high-...

[Phys. Rev. A 90, 043811] Published Thu Oct 09, 2014

]]>We study the electromagnetically induced transparency (EIT) effect with two individually addressed four-level Rydberg atoms subjected to the interatomic van der Waals interaction. We derive an effectively atomic Raman transition model where two ladders of the usual Rydberg EIT setting terminating at...

[Phys. Rev. A 90, 045801] Published Thu Oct 09, 2014

]]>Quantum theory in a global spacetime gives rise to nonlocal correlations, which cannot be explained causally in a satisfactory way; this motivates the study of theories with reduced global assumptions. Oreshkov, Costa, and Brukner [Nat. Commun. 3, 1092 (2012)10.1038/ncomms2076] proposed a framework ...

[Phys. Rev. A 90, 042106] Published Wed Oct 08, 2014

]]>Quantum Gaussian states can be considered as the majority of the practical quantum states used in quantum communications and more generally in quantum information. Here we consider their properties in relation to the geometrically uniform symmetry, a property of quantum states that greatly simplifie...

[Phys. Rev. A 90, 042309] Published Wed Oct 08, 2014

]]>We describe protocols for passive atomic clocks based on quantum interrogation of the atoms. Unlike previous techniques, our protocols are adaptive and take advantage of prior information about the clock's state. To reduce deviations from an ideal clock, each interrogation is optimized by means of a...

[Phys. Rev. A 90, 042310] Published Wed Oct 08, 2014

]]>We have calculated the intrinsic electric dipole moments (EDMs) of Xe129, Yb171, Ra225 atoms induced by the nuclear Schiff moment (NSM). We use the coupled perturbed Hartree-Fock [CPHF] framework to perform this calculation. In this work, the effects of electron correlation on atomic EDMs are studie...

[Phys. Rev. A 90, 042503] Published Wed Oct 08, 2014

]]>The angular correlation functions (ACFs) of a pair of Lyman-α photons emitted from H fragments in the photodissociation of a hydrogen molecule are measured at a 33.66-eV incident photon energy and at hydrogen gas pressures of approximately 0.1 and 1 Pa. The ACFs are measured for both opposite and no...

[Phys. Rev. A 90, 043405] Published Wed Oct 08, 2014

]]>We investigate whether nonadiabatic effects, rather than an initial longitudinal momentum spread, can explain the additional final momentum spread measured in strong-field ionization experiments with ultrafast laser pulses. We find that, when used consistently, a well-known nonadiabatic theory which...

[Phys. Rev. A 90, 043406] Published Wed Oct 08, 2014

]]>We theoretically propose a control scheme of temporal wave-packet separation for oriented molecules, based on nonresonant dynamic Stark effect (DSE) in the dipole limit. The proposed scheme exploits the fact that diabatic coupling between the lowest two potential-energy curves (PECs) depends on diat...

[Phys. Rev. A 90, 043407] Published Wed Oct 08, 2014

]]>We use a gray molasses operating on the D1 atomic transition to produce degenerate quantum gases of Li6 with a large number of atoms. This sub-Doppler cooling phase allows us to lower the initial temperature of 109 atoms from 500 to 40 μK in 2 ms. We observe that D1 cooling remains effective into a ...

[Phys. Rev. A 90, 043408] Published Wed Oct 08, 2014

]]>We experimentally study the spin dynamics of mesoscopic ensembles of ultracold magnetic spin-3 atoms located in two separated wells of an optical dipole trap. We use a radio-frequency sweep to selectively flip the spin of the atoms in one of the wells, which produces two separated spin domains of op...

[Phys. Rev. A 90, 043607] Published Wed Oct 08, 2014

]]>