In this Rapid Communication we investigate the fluctuation effects on the transport properties of unitary Fermi gases in the vicinity of the superfluid transition temperature Tc. Based on the time-dependent Ginzburg-Landau formalism of the Bose-Einstein condensate–BCS crossover, we investigate both ...

[Phys. Rev. A 90, 051602] Published Fri Nov 21, 2014

]]>In this work we introduce a distorted-wave method, based on the initial value representation approach of the quantum evolution operator, in order to improve the description of rainbow effects given by the surface eikonal (SE) model for diffraction from crystal surfaces produced by grazing scattering...

[Phys. Rev. A 90, 052718] Published Fri Nov 21, 2014

]]>We use the dressed potentials obtained in the adiabatic representation of two coupled channels to calculate s-wave Feshbach resonances in a three-dimensional spherically symmetric potential with an open channel interacting with a closed channel. Analytic expressions for the s-wave scattering length ...

[Phys. Rev. A 90, 052719] Published Fri Nov 21, 2014

]]>First-principles quantum-mechanical calculations of an intense-field ultrafast two-color core-hole stimulated Raman process in nitric oxide are presented. They employ the multiconfiguration time-dependent Hartree-Fock (MCTDHF) method with all 15 electrons active. These calculations demonstrate a rob...

[Phys. Rev. A 90, 053426] Published Fri Nov 21, 2014

]]>The large-distance behavior of the density-density correlation function in the Lieb-Liniger model at finite temperature is investigated by means of the recently derived nonlinear integral equations characterizing the correlation lengths. We present extensive numerical results covering all the physic...

[Phys. Rev. A 90, 053626] Published Fri Nov 21, 2014

]]>We discuss the effect of semitransparency in a quantum-Zeno-like interaction-free measurement setup, a quantum-physics based approach that might significantly reduce sample damage in imaging and microscopy. With an emphasis on applications in electron microscopy, we simulate the behavior of probe pa...

[Phys. Rev. A 90, 053840] Published Fri Nov 21, 2014

]]>We study how non-Markovianity of an open two-level system can be detected when continuously monitoring a part of its bosonic environment. Considering a physical scenario of an atom in a lossy cavity, we demonstrate that the properties of the time-dependent flux of the photons from the cavity allows ...

[Phys. Rev. A 90, 054101] Published Fri Nov 21, 2014

]]>[Phys. Rev. A 90, 059901] Published Fri Nov 21, 2014

]]>A distribution of thermal states given by random Hamiltonians with a local structure is studied and it is shown that the ensemble of these states monotonically approaches the unitarily invariant ensemble with decreasing temperature if all particles interact according to a single random interaction and achieves a state t-design at a temperature O(1/ log(t)).

[Phys. Rev. A 90, 050304] Published Thu Nov 20, 2014

]]>We present a cavity piezo-optomechanical system where microwave and optical degrees of freedom are coupled through an ultrahigh-frequency mechanical resonator. By utilizing the coherence among the three interacting modes, we demonstrate optical amplification, coherent absorption, and a more general ...

[Phys. Rev. A 90, 051801] Published Thu Nov 20, 2014

]]>A pseudopotential for positronium-atom interaction, based on electron-atom and positron-atom phase shifts, is constructed, and the phase shifts for Ps-Kr and Ps-Ar scattering are calculated. This approach allows us to extend the Ps-atom cross sections, obtained previously in the impulse approximatio...

[Phys. Rev. A 90, 052717] Published Thu Nov 20, 2014

]]>We compute the normal form description of a semiconductor laser near its threshold, with the sole assumption that the polarization be related to the electric field through the susceptibility (dependent on laser frequency and population inversion). We prove both analytically and numerically the possi...

[Phys. Rev. A 90, 053838] Published Thu Nov 20, 2014

]]>We study the impact of double- and triple-scattering contributions on coherent backscattering of laser light from saturated isotropic atoms in the helicity-preserving polarization channel. By using the recently proposed diagrammatic pump-probe approach, we analytically derive single-atom spectral re...

[Phys. Rev. A 90, 053839] Published Thu Nov 20, 2014

]]>We provide a twofold extension of Landau-Pollak uncertainty relations for mixed quantum states and for positive operator-valued measures, by recourse to geometric considerations. The generalization is based on metrics between pure states, having the form of a function of the square of the inner prod...

[Phys. Rev. A 90, 052114] Published Wed Nov 19, 2014

]]>When a pair of photons that are entangled in terms of their transverse modes, such as an orbital angular momentum (OAM) basis, propagates through atmospheric turbulence, the scintillation causes a decay of the entanglement. Here, we use numerical simulations to study how this decoherence process dep...

[Phys. Rev. A 90, 052115] Published Wed Nov 19, 2014

]]>In this paper, we report on a laser spectroscopy measurement of 84−87Rb isotopes in superfluid helium (He ii) at 1.8 K using laser–radio-frequency double-resonance spectroscopy. Rb ion beams (>60 MeV/u) provided by the RIKEN projectile fragment separator (RIPS) were injected and trapped into He i...

[Phys. Rev. A 90, 052516] Published Wed Nov 19, 2014

]]>By only using electric-dipole forbidden emission lines, in what we label forbidden-line spectroscopy, we identified several energy levels in cadmium-like tungsten, W26+. The spectrum was recorded at the Shanghai permanent-magnet electron beam ion trap in the visible region. The identifications were ...

[Phys. Rev. A 90, 052517] Published Wed Nov 19, 2014

]]>We discuss a possible one-dimensional trapping and cooling of atoms and molecules due to their nonresonant interaction with counterpropagating light pulse trains. The counterpropagating pulses form a one-dimensional trap for atoms and molecules and a properly chosen carrier frequency detuning from t...

[Phys. Rev. A 90, 053421] Published Wed Nov 19, 2014

]]>A resonantly driven bosonic Josephson junction supports stable collective excitations, or quasiparticles, which constitute analogs of the Trojan wave packets previously explored with Rydberg atoms in strong microwave fields. We predict a quantum beating effect between such symmetry-related many-body...

[Phys. Rev. A 90, 053622] Published Wed Nov 19, 2014

]]>Topological states of interacting many-body systems are at the focus of current research due to the exotic properties of their elementary excitations. In this paper we suggest a realistic experimental setup for the realization of a simple version of such a phase. We show how δ-interacting bosons hop...

[Phys. Rev. A 90, 053623] Published Wed Nov 19, 2014

]]>Variational solutions of the Boltzmann equation usually rely on the concept of linear response. We extend the variational approach for tight-binding models at high entropies to a regime far beyond linear response. We analyze both weakly interacting fermions and incoherent bosons on a lattice. We con...

[Phys. Rev. A 90, 053624] Published Wed Nov 19, 2014

]]>A theory of dispersive soliton of the self-induced transparency in a medium consisting of atoms or semiconductor quantum dots of two types is considered. A two-component medium is modeled by a set of two-level atoms of two types embedded into a conductive host material. These types of atoms correspo...

[Phys. Rev. A 90, 053835] Published Wed Nov 19, 2014

]]>We study the manipulation of Goos-Hänchen (GH) shifts for the reflected and transmitted probe light pulses injected into a cavity containing four-level configuration mercury atoms where the probe transition is in the ultraviolet (UV) region with a wavelength of 253.7nm. Different behaviors of the GH...

[Phys. Rev. A 90, 053836] Published Wed Nov 19, 2014

]]>We present a two-waveguide coupler which realizes complete achromatic all-optical switching. The coupling of the waveguides has a hyperbolic-secant shape, while the phase mismatch has a sign flip at the maximum of the coupling. We derive an analytic solution for the electric field propagation using ...

[Phys. Rev. A 90, 053837] Published Wed Nov 19, 2014

]]>The unextendible product basis is generalized to the unextendible entangled basis with any arbitrarily given Schmidt number k (UEBk) for any bipartite system Cd⊗Cd′ (2≤k<d≤d′), which can also be regarded as a generalization of the unextendible maximally entangled basis. A general way of construct...

[Phys. Rev. A 90, 054303] Published Wed Nov 19, 2014

]]>The robustness of the three-level transitionless quantum driving proposed by Giannelli and Arimondo [L. Giannelli and E. Arimondo, Phys. Rev. A 89, 033419 (2014)PLRAAN10.1103/PhysRevA.89.033419] is investigated. In the case when the excited state is barely populated during the evolution, its decay r...

[Phys. Rev. A 90, 055402] Published Wed Nov 19, 2014

]]>Open quantum systems are studied from the thermodynamical point of view unifying the principle of maximum informational entropy and the hypothesis of relaxation times hierarchy. The result of the unification is a non-Markovian and local-in-time master equation that provides a direct connection for d...

[Phys. Rev. A 90, 052112] Published Tue Nov 18, 2014

]]>We propose an implementation of a twin-paradox scenario in superconducting circuits, with velocities as large as a few percent of the speed of light. Ultrafast modulation of the boundary conditions for the electromagnetic field in a microwave cavity simulates a clock moving at relativistic speeds. S...

[Phys. Rev. A 90, 052113] Published Tue Nov 18, 2014

]]>A continuous-variable measurement-device-independent quantum key distribution (CV-MDI QKD) protocol using squeezed states is proposed where the two legitimate partners send Gaussian-modulated squeezed states to an untrusted third party to realize the measurement. Security analysis shows that the pro...

[Phys. Rev. A 90, 052325] Published Tue Nov 18, 2014

]]>We calculated, using seven realistic He4-He4 potentials in the literature, the Efimov spectra of the He4 trimer and tetramer and analyzed the universality of the systems. The three-(four-)body Schrödinger equations were solved fully nonadiabatically with the high-precision calculation method employe...

[Phys. Rev. A 90, 052514] Published Tue Nov 18, 2014

]]>It is shown that small energy-level splittings of resonance states in highly charged ions can be extracted from the angular correlations of characteristic x rays emitted in radiative cascades, which may ultimately be used for new tests of QED in highly charged ions.

[Phys. Rev. A 90, 052515] Published Tue Nov 18, 2014

]]>The electric-dipole and quadrupole polarizabilities of the 5s5p3P1o state and the C6 and C8 coefficients for the 1S0+1S0 and 1S0+3P1o dimers of strontium are calculated using a high-precision relativistic approach that combines configuration interaction and linearized coupled-cluster methods. Our re...

[Phys. Rev. A 90, 052715] Published Tue Nov 18, 2014

]]>The main limitation of most ultracold chemistry studies to date is the lack of an analysis of reaction products. Here, we discuss a generally tractable, rigorous theoretical framework for computing statistical product-state distributions for ultracold reactions in external fields. We show that field...

[Phys. Rev. A 90, 052716] Published Tue Nov 18, 2014

]]>Beams of helium atoms in Rydberg states with principal quantum number n=52, and traveling with an initial speed of 1950 m/s, have been accelerated, decelerated, and guided while confined in moving electric traps generated above a curved, surface-based electrical transmission line with a segmented ce...

[Phys. Rev. A 90, 053420] Published Tue Nov 18, 2014

]]>We investigate the structure and dynamics of a rotating superfluid Bose-Fermi mixture (SBFM) made of superfluid bosons and two-component (spin-up and -down) superfluid fermions. A ground-state phase diagram for the nonrotating case of a SBFM with specific parameters is given, where the ground-state ...

[Phys. Rev. A 90, 053621] Published Tue Nov 18, 2014

]]>We propose and analyze a circuit that implements a nonlinear coupling between two superconducting microwave resonators. The resonators are coupled through a superconducting quantum interference device that terminates one of the resonators. This produces a nonlinear interaction of the standard optome...

[Phys. Rev. A 90, 053833] Published Tue Nov 18, 2014

]]>We introduce a theoretical framework which is suitable for the description of all spatial and time-multiplexed periodic single-photon sources realized or proposed thus far. Our model takes into account all possibly relevant loss mechanisms. This statistical analysis of the known schemes shows that m...

[Phys. Rev. A 90, 053834] Published Tue Nov 18, 2014

]]>We consider theoretically a closed (zero-dimensional) semiconductor microcavity where a confined vacuum photonic mode is coupled to electrons in the valence band of the semiconductor. It is shown that vacuum-induced virtual electron transitions between valence and conduction bands result in renormal...

[Phys. Rev. A 90, 055802] Published Tue Nov 18, 2014

]]>We report on parallel production of Bose-Einstein condensates (BECs) in steerable, multiplexed crossed optical dipole traps. Using a conventional trap-weakening evaporation scheme, where the optical trapping power is lowered, we obtain an array of up to four independent BECs. To improve evaporation ...

[Phys. Rev. A 90, 051401] Published Mon Nov 17, 2014

]]>The violation of the Cauchy-Schwarz and Bell inequalities ranks among the major evidence of the genuinely quantum nature of an emitter. The conventional theoretical approaches associate operators with spectral lines to study correlations between photons from real-state transitions. Instead, we use a...

[Phys. Rev. A 90, 052111] Published Mon Nov 17, 2014

]]>We suggest an all-optical quantum memory scheme which is based on the off-resonant Raman interaction of a signal quantum field and a strong control field in a three-level atomic medium in the case where the control field has a spatially varying frequency across the beam, called a spatial chirp. We s...

[Phys. Rev. A 90, 052322] Published Mon Nov 17, 2014

]]>Physical principles constrain the way nonlocal correlations can be distributed among distant parties. These constraints are usually expressed by monogamy relations that bound the amount of Bell inequality violation observed among a set of parties by the violation observed by a different set of parti...

[Phys. Rev. A 90, 052323] Published Mon Nov 17, 2014

]]>We consider the problem of time-optimal control of a continuous bosonic quantum system subject to the action of a Markovian dissipation. In particular, we consider the case of a one-mode Gaussian quantum system prepared in an arbitrary initial state and which relaxes to the steady state due to the a...

[Phys. Rev. A 90, 052324] Published Mon Nov 17, 2014

]]>We investigate the dispersive Casimir–Polder interaction between a rubidium atom and a suspended graphene sheet subjected to an external magnetic field B. We demonstrate that this concrete physical system allows for an unprecedented control of dispersive interactions at micro- and nanoscales. Indeed...

[Phys. Rev. A 90, 052511] Published Mon Nov 17, 2014

]]>We present here a model of the exchange-correlation hole for strongly correlated systems using a simple nonlocal generalization of the Wigner-Seitz radius. The model behaves similarly to the strictly correlated electron approach, which gives the infinitely correlated limit of density functional theo...

[Phys. Rev. A 90, 052512] Published Mon Nov 17, 2014

]]>Relativistic ab initio calculations have been performed to assess the suitability of RaF for experimental search of P- and T-and-P–violating interactions. The parameters of P- and T,P-odd terms of the spin-rotational Hamiltonian have been calculated for the 2Σ electronic ground state of the RaF223 m...

[Phys. Rev. A 90, 052513] Published Mon Nov 17, 2014

]]>We have measured the absolute double-differential cross sections (DDCS) for electron emission in ionization of He and Ne atoms under the impact of 6-MeV/u C6+ ions. Data were collected between 1 and 500 eV for He, while for Ne this range was extended up to 1000 eV. The angular ranges covered in the ...

[Phys. Rev. A 90, 052714] Published Mon Nov 17, 2014

]]>We study the formation of highly excited neutral atoms during the breakup of strongly driven molecules. Past work on this significant phenomenon has shown that during the formation of highly excited neutral atoms (H*) during the breakup of H2 in a linear laser field the electron that escapes does so...

[Phys. Rev. A 90, 053419] Published Mon Nov 17, 2014

]]>We present a systematic derivation of the effective action for interacting vortices in a nonrelativistic two-dimensional superfluid described by the Gross-Pitaevskii equation by integrating out longitudinal fluctuations of the order parameter. There are no logarithmically divergent coefficients in t...

[Phys. Rev. A 90, 053617] Published Mon Nov 17, 2014

]]>We study the dynamics in a one-dimensional hard-core Bose gas with power-law hopping after an abrupt reduction of the hopping range using the time-dependent density-matrix renormalization-group and bosonization techniques. In particular, we focus on the destruction of the Bose-Einstein condensate (B...

[Phys. Rev. A 90, 053618] Published Mon Nov 17, 2014

]]>We study the virial expansion for three-dimensional Bose and Fermi gases at finite temperature using an approximation that only considers two-body processes and is valid for high temperatures and low densities. The first virial coefficients are computed and the second is exact. The results are obtai...

[Phys. Rev. A 90, 053619] Published Mon Nov 17, 2014

]]>We investigate the BCS-BEC crossover in a bilayer system of fermionic dipoles at zero temperature using the fixed-node diffusion Monte Carlo technique. The dipoles are confined on two parallel planes separated by a distance λ and are aligned perpendicular to the planes by an external field. The inte...

[Phys. Rev. A 90, 053620] Published Mon Nov 17, 2014

]]>Linear optomechanical photon-phonon couplings in the membrane-in-the-middle setup can be enhanced by taking a multielement approach as it was recently shown [A. Xuereb, C. Genes, and A. Dantan, Phys. Rev. Lett. 109, 223601 (2012)PRLTAO10.1103/PhysRevLett.109.223601]. The particular example considere...

[Phys. Rev. A 90, 053831] Published Mon Nov 17, 2014

]]>Based on a single atom coupled to a fiber-coupled, chip-based microresonator [B. Dayan et al., Science 319, 1062 (2008)SCIEAS10.1126/science.1152261], we put forward a scheme to generate optical frequency combs at driving laser powers as low as a few nanowatts. Using state-of-the-art experimental pa...

[Phys. Rev. A 90, 053832] Published Mon Nov 17, 2014

]]>We propose a dissipative scheme to generate a maximally entangled state for two Λ-type atoms trapped in an optical cavity. Different from the unitary-dynamics-based scheme, our work shows that both atomic spontaneous emission and cavity decay are no longer detrimental, but necessary for entanglement...

[Phys. Rev. A 90, 054302] Published Mon Nov 17, 2014

]]>We investigate the fine-grained uncertainty relations for qubit systems by measurements corresponding respectively to two and three spin operators. Then we derive the general bound for a combination of two probabilities of projective measurements in mutually unbiased bases in d-dimensional Hilbert s...

[Phys. Rev. A 90, 052110] Published Fri Nov 14, 2014

]]>We investigate resource requirements for a fault-tolerant quantum Fourier transform. The quantum Fourier transform is a basic subroutine for quantum algorithms which provide an exponential speedup over known classical ones, such as Shor's algorithm for factoring. To implement single-qubit rotations ...

[Phys. Rev. A 90, 052318] Published Fri Nov 14, 2014

]]>In the postprocessing of quantum key distribution, the raw key bits from the mismatched-basis measurements, where two parties use different bases, are normally discarded. Here, we propose a postprocessing method that exploits measurement statistics from mismatched-basis cases and prove that incorpor...

[Phys. Rev. A 90, 052319] Published Fri Nov 14, 2014

]]>A scheme for suppressing the correlated noise in signals transmitted over the bosonic Gaussian memory channels is proposed. This is a compromise solution rather than removing the noise completely. The scheme is based on linear optical elements, two N-port splitters and N number of phase flips. The p...

[Phys. Rev. A 90, 052320] Published Fri Nov 14, 2014

]]>We derive a hierarchy of separability criteria for multimode continuous-variable systems. They permit one to study in a unified way the k-partite entanglement of broad classes of Gaussian and non-Gaussian states. With specific examples we demonstrate the strength of the criteria, and we discuss thei...

[Phys. Rev. A 90, 052321] Published Fri Nov 14, 2014

]]>We show through numerical investigations that the ground-state correlation energies of atomic ions follow an unexpectedly simple scaling relation, Ec≈Z4/3fc(Z/N), where N is the number of electrons, Z is the atomic number, and fc is a universal function, for which an analytic expression with a one-p...

[Phys. Rev. A 90, 052510] Published Fri Nov 14, 2014

]]>We consider the theory of multiple-particle fragmentation processes in the light of modern multihit position-sensitive detection. First, we give a formulation of time-independent many-body scattering theory as a direct generalization of standard textbook two-body potential scattering but in such a w...

[Phys. Rev. A 90, 052712] Published Fri Nov 14, 2014

]]>We report elastic integral cross sections for low-energy electron scattering by gas-phase dimethyl sulfide and dimethyl disulfide, obtained with the Schwinger multichannel method with pseudopotentials. Our symmetry-resolved cross sections for dimethyl sulfide reveal that the single broad structure a...

[Phys. Rev. A 90, 052713] Published Fri Nov 14, 2014

]]>Ultrashort nonresonant electromagnetic pulses applied to effective one-electron systems may operate on the electronic state as a position or momentum translation operator. As derived here, extension to many-body correlated systems exposes qualitatively new aspects. For instance, to the lowest order ...

[Phys. Rev. A 90, 053417] Published Fri Nov 14, 2014

]]>Recently introduced time-dependent renormalized-natural-orbital theory (TDRNOT) is tested on nonsequential double ionization (NSDI) of a numerically exactly solvable one-dimensional model He atom subject to few-cycle, 800-nm laser pulses. NSDI of atoms in strong laser fields is a prime example of no...

[Phys. Rev. A 90, 053418] Published Fri Nov 14, 2014

]]>We theoretically analyze parametric amplification as a means to produce dichroism based on the orbital angular momentum (OAM) of an incident signal field. The nonlinear interaction is shown to provide differential gain between signal states of differing OAM, the peak gain occurring at half the OAM o...

[Phys. Rev. A 90, 053828] Published Fri Nov 14, 2014

]]>We analyze the optical properties of the so-called invisible lenses in the wave-optics regime and show that they are practically invisible for a discrete set of frequencies. For other frequencies, the phase delay of the waves that pass through the lens compared to those that do not disturbs the outg...

[Phys. Rev. A 90, 053829] Published Fri Nov 14, 2014

]]>We report that nonlocal nonlinear media allow a controlled interaction among coherent solitons with a relative tilt previously imposed, resulting in the generation of rotary self-trapped beams. We demonstrate that two initially separated fundamental solitons can interact, generating stable rotating ...

[Phys. Rev. A 90, 053830] Published Fri Nov 14, 2014

]]>We go beyond the approximate series expansions used in the dispersion theory of finite-size atoms. We demonstrate that a correct, and nonperturbative, theory dramatically alters the dispersion self-energies of atoms. The nonperturbed theory gives as much as 100% corrections compared to the tradition...

[Phys. Rev. A 90, 054502] Published Fri Nov 14, 2014

]]>We study the XY model with infinite-range interactions (Lipkin-Meshkov-Glick model) in the presence of dissipation from spontaneous decay. We show that independent and collective decay lead to qualitatively different phase transitions of the steady state, even though the phase boundary is the same. ...

[Phys. Rev. A 90, 052109] Published Thu Nov 13, 2014

]]>We analyze a scheme for generating entanglement between two spinor Bose-Einstein condensates (BECs). The BECs are off-resonantly coupled to a common photon mode and are controlled by external lasers to induce a SzSz interaction, where Sz is the total spin of the BEC. We directly simulate the scheme ...

[Phys. Rev. A 90, 052315] Published Thu Nov 13, 2014

]]>The surface code cannot be used when qubits vanish during computation; instead, a variant known as the topological cluster state is necessary. It has a gate error threshold of 0.75% and requires only nearest-neighbor interactions on a two-dimensional (2D) array of qubits. Previous work on loss toler...

[Phys. Rev. A 90, 052316] Published Thu Nov 13, 2014

]]>We propose a strategy to improve the performance of the quantum adiabatic algorithm (QAA) on an NP-hard (nondeterministic-polynomial-time-hard) problem exact cover, by increasing the ground-state degeneracy of the problem Hamiltonian. Our strategy is based on the empirical finding that for the QAA t...

[Phys. Rev. A 90, 052317] Published Thu Nov 13, 2014

]]>We have calculated ac polarizabilities of the 23S and 21S states of both He4 and He3 in the range 318 nm to 2.5 μm and determined the magic wavelengths at which these polarizabilities are equal for either isotope. The calculations, only based on available ab initio tables of level energies and Einst...

[Phys. Rev. A 90, 052508] Published Thu Nov 13, 2014

]]>A high-precision relativistic calculation of Cd-like Nd12+,Sm14+ and Sn-like Pr9+,Nd10+ atomic properties is carried out using an approach that combines configuration interaction and a linearized coupled-cluster method. These ions have long-lived metastable states with transitions accessible by lase...

[Phys. Rev. A 90, 052509] Published Thu Nov 13, 2014

]]>We demonstrate control of the differential Zeeman shift between clock states of ultracold rubidium atoms by means of nonresonant microwave dressing. Using the dc field dependence of the microwave detuning, we suppress the first- and second-order differential Zeeman shift in magnetically trapped Rb87...

[Phys. Rev. A 90, 053416] Published Thu Nov 13, 2014

]]>Spatial light modulator (SLM) controlled transmission of light through opaque media is a relatively new experimental method with wide applications in various fields. While there has been a surge in research into the technique, there has been little work reported considering the effects of various ex...

[Phys. Rev. A 90, 053826] Published Thu Nov 13, 2014

]]>We investigate the possibility of using the independence of the transmitted speckle pattern on the illumination condition as a signature of Anderson localization in a single configuration of a two-dimensional and open disordered medium. The analysis is based on exact numerical simulations of multipl...

[Phys. Rev. A 90, 053827] Published Thu Nov 13, 2014

]]>The semiclassical perturbation method developed by Henkel et al. [J. Phys. II 4, 1955 (1994)JPAHER10.1051/jp2:1994242] to model cold-atom diffraction by optical standing waves, is applied to the diffraction of fast atoms on crystal surfaces at grazing incidence (GIFAD or FAD). We first show that the...

[Phys. Rev. A 90, 054701] Published Thu Nov 13, 2014

]]>Electron-positron-pair creation in collisions of a modulated laser pulse with a high-energy photon (nonlinear Breit-Wheeler process) is studied by means of strong-field quantum electrodynamics. It is shown that the driving pulse modulations lead to the appearance of comb structures in the energy spe...

[Phys. Rev. A 90, 052108] Published Wed Nov 12, 2014

]]>In principle, quantum key distribution (QKD) offers unconditional security based on the laws of physics. Unfortunately, all previous QKD experiments assume perfect state preparation in their security analysis. Therefore, the generated key is not proven to be secure in the presence of unavoidable mod...

[Phys. Rev. A 90, 052314] Published Wed Nov 12, 2014

]]>The permanent electric dipole moment of the X2Σ+ electronic ground state of the strontium monofluoride molecule is calculated using a relativistic coupled-cluster method. Our result is compared with those of other calculations and that of experiment. Individual contributions arising from different p...

[Phys. Rev. A 90, 052507] Published Wed Nov 12, 2014

]]>We have measured fully differential cross sections for ionization of H2 by 75-keV proton impact. The coherence length of the projectile beam was varied by changing the distance between a collimating slit and the target. By comparing the cross sections measured for large and small coherence lengths p...

[Phys. Rev. A 90, 052710] Published Wed Nov 12, 2014

]]>Bond oscillation, a phenomenon characteristic of the molecular electron-density distribution in momentum space, is demonstrated for the 1σg molecular orbital of H2 with an (e, 2e) experiment at large momentum transfer. Analysis of the experimental data in terms of two-center interference effects has...

[Phys. Rev. A 90, 052711] Published Wed Nov 12, 2014

]]>Several kinds of interference effects in laser-assisted photoionization of H2+ molecular targets are theoretically investigated by means of a Coulomb-Volkov model. The photoelectron angular distributions in the single-photon ionization reaction are compared to more elaborated results, and the influe...

[Phys. Rev. A 90, 053414] Published Wed Nov 12, 2014

]]>We have studied the influence of a linearly polarized laser field on the dynamics of low (e,2e) collisions in atomic hydrogen. The influence of the laser on the target states is treated using a first-order perturbation approach. The continuum states of the scattered and ejected electrons are describ...

[Phys. Rev. A 90, 053415] Published Wed Nov 12, 2014

]]>We suggest that nonequilibrium Bose-Einstein condensates may occur in time-periodically driven interacting Bose gases. Employing the model of a periodically forced bosonic Josephson junction, we demonstrate that resonance-induced ground-state-like many-particle Floquet states possess an almost perfe...

[Phys. Rev. A 90, 053614] Published Wed Nov 12, 2014

]]>Recent experimental realizations of artificial gauge fields for cold atoms are promising for generating steady states carrying a mass current in strongly correlated systems, such as the Bose-Hubbard model. Moreover, a homogeneous condensate confined by hard-wall potentials from laser sheets has been...

[Phys. Rev. A 90, 053615] Published Wed Nov 12, 2014

]]>We develop theory for fluctuations in atom number and spin within finite-sized cells of a spinor Bose-Einstein condensate. This theory provides a model of measurements that can be performed in current experiments using finite resolution in situ imaging. We develop analytic results for quantum and th...

[Phys. Rev. A 90, 053616] Published Wed Nov 12, 2014

]]>We employ coupled wave theory to enumerate the lasing modes of structurally chiral lasers. The elliptical modes are shown to be fundamentally distinct from those of a scalar distributed feedback laser. High threshold modes are shown to lase with the opposite chirality as the active medium, in contra...

[Phys. Rev. A 90, 053824] Published Wed Nov 12, 2014

]]>Single photons exhibit nonclassical, counterintuitive behavior that can be exploited in the developing field of quantum technology. They are needed for various applications such as quantum key distribution, optical quantum information processing, quantum computing, intensity measurement standards, a...

[Phys. Rev. A 90, 053825] Published Wed Nov 12, 2014

]]>We study the influence of a detector on the decay law of a quantum state whose undisturbed survival probability is purely exponential. In particular, we consider a detector with a finite energy band of detection, i.e., it interacts only with decay products having an energy within a certain range of ...

[Phys. Rev. A 90, 052107] Published Tue Nov 11, 2014

]]>We demonstrate, in the regime of ultrastrong matter-field coupling, the strong connection between the dynamical Casimir effect (DCE) and the performance of quantum-information protocols. Our results are illustrated by means of a realistic quantum communication channel and show that the DCE is a fund...

[Phys. Rev. A 90, 052313] Published Tue Nov 11, 2014

]]>We study the dynamics of a dipolar Bose-Einstein condensate, like, for example, a Cr52 or Dy164 condensate, interacting with a superconducting surface. The magnetic dipole moments of the atoms in the Bose-Einstein condensate induce eddy currents in the superconductor. The magnetic field generated by...

[Phys. Rev. A 90, 052709] Published Tue Nov 11, 2014

]]>The many-electron weak-field asymptotic theory (ME-WFAT) of tunneling ionization [Tolstikhin et al., Phys. Rev. A 89, 013421 (2014)PLRAAN10.1103/PhysRevA.89.013421] is applied to atoms. The procedure to extract the asymptotic coefficient of a Dyson orbital needed to implement the ME-WFAT from many-e...

[Phys. Rev. A 90, 053413] Published Tue Nov 11, 2014

]]>We use a finite-temperature effective field theory recently developed for superfluid Fermi gases to investigate the properties of dark solitons in these superfluids. Our approach provides an analytic solution for the dip in the order parameter and the phase profile across the soliton, which can be c...

[Phys. Rev. A 90, 053613] Published Tue Nov 11, 2014

]]>We study single-photon transport in a single-mode waveguide, in which two-level atoms in spatial superpositions are embedded. We find that the transmission of the photon can be used as a nondestructive probe for the coherence of the superposition. Under certain trapping configurations, the protocol ...

[Phys. Rev. A 90, 053821] Published Tue Nov 11, 2014

]]>We propose a scheme for single-atom, quantum control of the direction of propagation of a coherent field incident, via a tapered fiber, upon a microtoroidal whispering-gallery-mode (WGM) resonator. The scheme involves overcoupling of the fiber taper to the resonator and strong coupling of an atom to...

[Phys. Rev. A 90, 053822] Published Tue Nov 11, 2014

]]>We study a modified Ramsey spectroscopy technique employing slowly decaying states for quantum metrology applications using dense ensembles. While closely positioned atoms exhibit super-radiant collective decay and dipole-dipole induced frequency shifts, recent results [L. Ostermann, H. Ritsch, and ...

[Phys. Rev. A 90, 053823] Published Tue Nov 11, 2014

]]>Homomorphic encryption is a form of encryption which allows computation to be carried out on the encrypted data without the need for decryption. The success of quantum approaches to related tasks in a delegated computation setting has raised the question of whether quantum mechanics may be used to a...

[Phys. Rev. A 90, 050303] Published Mon Nov 10, 2014

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