We investigate polyatomic ultralong-range Rydberg molecules consisting of three ground-state atoms bound to a Rydberg atom via $s$- and $p$-wave interactions. By employing the finite basis set representation of the unperturbed Rydberg electron Green's function we reduce the computational effort to solve…

[Phys. Rev. A 94, 012516] Published Thu Jul 28, 2016

]]>A Kohn-Sham time-dependent local-density-functional scheme is utilized to predict attosecond time delays of xenon $4d$ photoionization that involves the $4d$ giant dipole resonance and Cooper minimum. The fundamental effect of electron correlations to uniquely determine the delay at both regions is demo…

[Phys. Rev. A 94, 013429] Published Thu Jul 28, 2016

]]>We study the transport, decoherence, and the dissipation of the kinetic energy of a mobile impurity interacting with a bath of free fermions in a one-dimensional lattice. Numerical simulations are made with the time-evolving block decimation method, starting from a state where the impurity and bath …

[Phys. Rev. A 94, 013619] Published Thu Jul 28, 2016

]]>We propose a method to break the chiral symmetry of light in traveling wave resonators by coupling the optical modes to a lossy channel. Through the engineered dissipation, an indirect dissipative coupling between two oppositely propagating modes can be realized. Combined with reactive coupling, it …

[Phys. Rev. A 94, 013848] Published Thu Jul 28, 2016

]]>Recent work has unveiled a new class of optical systems that can exhibit the characteristic features of superfluidity. One such system relies on the repulsive photon-photon interaction that is mediated by a thermal optical nonlinearity and is therefore inherently nonlocal due to thermal diffusion. H…

[Phys. Rev. A 94, 013849] Published Thu Jul 28, 2016

]]>Quantum nonclassicality is the basic building stone for the vast majority of quantum information applications and methods of its generation are at the forefront of research. One of the obstacles any method needs to clear is the looming presence of decoherence and noise which act against the nonclass…

[Phys. Rev. A 94, 013850] Published Thu Jul 28, 2016

]]>Microdisk cavities with a smoothly deformed boundary allow for highly directional light emission. The conventional direct problem is to determine the far-field emission pattern of an optical mode for a given cavity shape by solving Maxwell's equations. We introduce the inverse problem of finding the…

[Phys. Rev. A 94, 013851] Published Thu Jul 28, 2016

]]>It is well known that standing waves, as special bound states in the radiation continuum, may exist on a periodic array of dielectric cylinders at a discrete set of frequencies if the medium is linear. Recent numerical studies indicate that nonlinear standing waves could exist continuously with resp…

[Phys. Rev. A 94, 013852] Published Thu Jul 28, 2016

]]>Frequent observation of a quantum system leads to quantum Zeno physics, where the system evolution is constrained to states commensurate with the measurement outcome. We show that, more generally, the system can evolve between such states through higher-order virtual processes that pass through stat…

[Phys. Rev. A 94, 012118] Published Wed Jul 27, 2016

]]>We investigate the problem of what evolutions an open quantum system described by a time-local master equation can undergo with universal coherent controls. A series of conditions is given which exclude channels from being reachable by any unitary controls, assuming that the coupling to the environm…

[Phys. Rev. A 94, 012119] Published Wed Jul 27, 2016

]]>The role of the generalized Pauli constraints (GPCs) in higher spatial dimensions and by incorporating spin degrees of freedom is systematically explored for a system of interacting fermions confined by a harmonic trap. Physical relevance of the GPCs is confirmed by analytical means for the ground s…

[Phys. Rev. A 94, 012120] Published Wed Jul 27, 2016

]]>Fock states are a fundamental resource for many quantum technologies such as quantum metrology. While much progress has been made in single-photon source technologies, preparing Fock states with a large photon number remains challenging. We present and analyze a bootstrapped approach for nondetermin…

[Phys. Rev. A 94, 012344] Published Wed Jul 27, 2016

]]>We consider the van der Waals force involving excited atoms in general environments, constituted by magnetodielectric bodies. We develop a dynamical approach studying the dynamics of the atoms and the field, mutually coupled. When only one atom is excited, our dynamical theory suggests that for larg…

[Phys. Rev. A 94, 012705] Published Wed Jul 27, 2016

]]>We present our experimental investigation of an optical Raman transition between the magnetic clock states of ${}^{87}\mathrm{Rb}$ in an atom chip magnetic trap. The transfer of atomic population is induced by a pair of diode lasers which couple the two clock states off-resonantly to an intermediate state manifold.…

[Phys. Rev. A 94, 013427] Published Wed Jul 27, 2016

]]>The properties of molecule-optical elements such as lenses or prisms based on the interaction of molecules with optical fields depend in a crucial way on the molecular quantum state and its alignment created by the optical field. Herein, we consider the effects of state-dependent alignment in estima…

[Phys. Rev. A 94, 013428] Published Wed Jul 27, 2016

]]>The coherent photon scattering of atoms in an atomic array is studied. It is found that due to cooperative photon exchanges, the excitation probability of an atom in an array parallel to the direction of laser propagation ($\widehat{\mathit{k}}$) will either grow or decay along $\widehat{\mathit{k}}$, depending on the detuning of the lase…

[Phys. Rev. A 94, 013847] Published Wed Jul 27, 2016

]]>Witnessing entanglement is crucial in quantum information processing. With properly preparing ancillary states, it has been shown previously that genuine entanglement can be witnessed without trusting measurement devices. In this work we generalize the scenario and show that generic multipartite ent…

[Phys. Rev. A 94, 012343] Published Tue Jul 26, 2016

]]>Dynamic second-order hyperpolarizabilities of atomic noble gases and their multiply ionized ions are computed using *ab initio* multiconfigurational self-consistent field cubic response theory. For each species, the calculations are performed at wavelengths ranging from the static regime to those abou…

[Phys. Rev. A 94, 012514] Published Tue Jul 26, 2016

]]>Nonresonant spontaneous bremsstrahlung of an electron scattered by a nucleus in the field of two moderately strong pulsed waves is studied theoretically. The process is studied in detail within the interference kinematic region. This region is determined by scattering of particles in the same plane …

[Phys. Rev. A 94, 013424] Published Tue Jul 26, 2016

]]>We study the photon energy sharing between the photoelectron and the nuclei in the process of above-threshold multiphoton dissociative ionization of CO molecules by measuring the joint energy spectra. The experimental observation shows that the electron-nuclear energy sharing strongly depends on the…

[Phys. Rev. A 94, 013425] Published Tue Jul 26, 2016

]]>The capability of generating two intense, femtosecond x-ray pulses with a controlled time delay opens the possibility of performing time-resolved experiments for x-ray-induced phenomena. We have applied this capability to study the photoinduced dynamics in diatomic molecules. In molecules composed o…

[Phys. Rev. A 94, 013426] Published Tue Jul 26, 2016

]]>Tripartite entangled states, such as Greenberger-Horne-Zeilinger and W states, are typically generated by manipulating two pairs of polarization-entangled photons in bulk optics. Here we propose a scheme to generate W states that are entangled in the energy degree of freedom in an integrated optical…

[Phys. Rev. A 94, 013845] Published Tue Jul 26, 2016

]]>High-order-harmonic generation in α-quartz $\mathrm{Si}{\mathrm{O}}_{2}$ is theoretically investigated under a strong laser field by solving the extended semiconductor Bloch equations. The accurate band structures as well as dipole moments between different bands are obtained from state-of-the-art first-principles calculati…

[Phys. Rev. A 94, 013846] Published Tue Jul 26, 2016

]]>We first show that the many-body Hamiltonian governing the physical properties of an alkaline-earth ${}^{173}\mathrm{Yb}$ Fermi gas across the recently realized orbital Feshbach resonance is exactly analogous to that of two-band $s$-wave superconductors with contact interactions; i.e., even though the free-particle b…

[Phys. Rev. A 94, 011604(R)] Published Mon Jul 25, 2016

]]>The photonic analog of the paramagnetic to spin-glass phase transition in disordered magnetic systems, signaled by the phenomenon of replica symmetry breaking, has been reported using random lasers as the photonic platform. We report here a demonstration of replica symmetry breaking in a one-dimensi…

[Phys. Rev. A 94, 011801(R)] Published Mon Jul 25, 2016

]]>Although superconducting systems provide a promising platform for quantum computing, their networking poses a challenge because they cannot be interfaced to light, the medium used to send quantum signals through channels at room temperature. We show that mechanical oscillators can mediate such coupl…

[Phys. Rev. A 94, 012340] Published Mon Jul 25, 2016

]]>We consider a finite one-dimensional Heisenberg $\mathit{XYZ}$ spin chain under the influence of a dissipative Lindblad environment obeying the Born-Markovian constraint in presence of an external magnetic field with closed and open boundary conditions. We present an exact numerical solution for the Lindblad m…

[Phys. Rev. A 94, 012341] Published Mon Jul 25, 2016

]]>The need for Hamiltonians with many-body interactions arises in various applications of quantum computing. However, interactions beyond two-body are difficult to realize experimentally. Perturbative gadgets were introduced to obtain arbitrary many-body effective interactions using Hamiltonians with …

[Phys. Rev. A 94, 012342] Published Mon Jul 25, 2016

]]>The Casimir-Polder interaction between an atom and a multilayered system composed of infinitely thin planes is considered using the $\zeta $-function regularization approach with zero-point energies summation. As a prototype material, each plane is represented by a graphene sheet, an atomically thin layer …

[Phys. Rev. A 94, 012513] Published Mon Jul 25, 2016

]]>We present a detailed analysis of the propagation dynamics of short and intense circularly polarized pulses in an aligned diatomic gas. Compared to linearly polarized intense pulses, high harmonic generation (HHG) and the coherent generation of attosecond pulses in the intense-circular-polarization …

[Phys. Rev. A 94, 013421] Published Mon Jul 25, 2016

]]>We theoretically investigate the electron interference dynamics of ${{\mathrm{H}}_{2}}^{+}$ in an intense infrared laser field. At intermediate internuclear distances, an interference fringe appears in the electron momentum distribution. By tracing the time evolution of the electron density, we identify an internal scat…

[Phys. Rev. A 94, 013422] Published Mon Jul 25, 2016

]]>Angular dependence of photoemission time delay for the valence $n{p}_{3/2}$ and $n{p}_{1/2}$ subshells of Ar, Kr, and Xe is studied in the dipole relativistic random phase approximation. Strong angular anisotropy of the time delay is reproduced near respective Cooper minima while the spin-orbit splitting affects …

[Phys. Rev. A 94, 013423] Published Mon Jul 25, 2016

]]>We further examine a theory of phase contrast imaging (PCI) of cold atomic gases, first introduced by us in Phys. Rev. Lett. **112**, 233602 (2014). We model the PCI measurement by directly calculating the entangled state between the light and the atoms due to the ac Stark shift, which induces a conditi…

[Phys. Rev. A 94, 013617] Published Mon Jul 25, 2016

]]>We study numerically the evolution of Bose-Einstein condensate in the Sinai-oscillator trap described by the Gross-Pitaevskii equation in two dimensions. In the absence of interactions, this trap mimics the properties of Sinai billiards where the classical dynamics is chaotic and the quantum evoluti…

[Phys. Rev. A 94, 013618] Published Mon Jul 25, 2016

]]>We propose using a nonlinear Mach-Zehnder interferometer (NMZI) to efficiently prepare photonic quantum states from a classical input. We first analytically investigate the simple NMZI that can filtrate a single-photon state from weak coherent state by preferentially blocking a two-photon component.…

[Phys. Rev. A 94, 013841] Published Mon Jul 25, 2016

]]>A scheme of high-precision two- and three-dimensional (3D) atom localization is proposed and analyzed by using a density matrix method for a five-level atom-light coupling scheme. In this system four strong laser components (which could be standing waves) couple a pair of atomic internal states to a…

[Phys. Rev. A 94, 013842] Published Mon Jul 25, 2016

]]>We describe an experiment demonstrating the possibility to generate collinear indistinguishable x-ray photon pairs with a highly suppressed background. By choosing angles near 90 degrees between the detectors and the pump beam, where the pump polarization is in the scattering plane, we improve the s…

[Phys. Rev. A 94, 013843] Published Mon Jul 25, 2016

]]>We analyze the radiation-pressure-induced interaction of mirror motion and light fields in Michelson-type interferometers used for the detection of gravitational waves and for fundamental research in tabletop quantum optomechanical experiments, focusing on the asymmetric regime with a (slightly) unb…

[Phys. Rev. A 94, 013844] Published Mon Jul 25, 2016

]]>Here we show that noisy coupling can lead to diffusive lossless energy transfer between individual quantum systems retaining a quantum character leading to entangled stationary states. Coherence may flow diffusively while being summarily preserved even when energy exchange is absent. Diffusive dynam…

[Phys. Rev. A 94, 012116] Published Fri Jul 22, 2016

]]>A single-step Eriksen transformation of $1{S}_{1/2},\phantom{\rule{0.16em}{0ex}}2{P}_{1/2}$, and $2{P}_{3/2}$ states of the relativistic hydrogenlike atom is performed exactly by expressing each transformed function (TF) as a linear combination of eigenstates of the Dirac Hamiltonian. The TFs, which are four-component spinors with vanishing two …

[Phys. Rev. A 94, 012117] Published Fri Jul 22, 2016

]]>Quantum systems allow one to sense physical parameters beyond the reach of classical statistics—with resolutions greater than $1/N$, where $N$ is the number of constituent particles independently probing a parameter. In the canonical phase-sensing scenario the Heisenberg limit $1/{N}^{2}$ may be reached, which…

[Phys. Rev. A 94, 012339] Published Fri Jul 22, 2016

]]>A Rydberg-atom–ion hybrid system is proposed for quantum-information and quantum-simulation applications with a micrometer interaction range. This scheme is expected to bring flexibility in manipulating the quantum states in the hybrid system while retaining some of the advantages of the trapped-ion scheme.

[Phys. Rev. A 94, 013420] Published Fri Jul 22, 2016

]]>We construct a theory for Bose-Einstein condensation of light in nanofabricated semiconductor microcavities. We model the semiconductor by one conduction and one valence band which consist of electrons and holes that interact via a Coulomb interaction. Moreover, we incorporate screening effects by u…

[Phys. Rev. A 94, 013615] Published Fri Jul 22, 2016

]]>We apply the multiconfigurational time-dependent Hartree method for indistinguishable particles (MCTDH-X) to systems of bosons or fermions in lattices described by Hubbard-type Hamiltonians with long-range or short-range interparticle interactions. The wave function is expanded in a variationally op…

[Phys. Rev. A 94, 013616] Published Fri Jul 22, 2016

]]>The present work is devoted to the theoretical study of the nonreciprocal optical properties in hybrid (isotropic and anisotropic) periodic multilayers for photon energy values chosen close to the electronic energy gaps of semiconductors (excitons). The optical properties of these resonant nonmagnet…

[Phys. Rev. A 94, 013840] Published Fri Jul 22, 2016

]]>We provide a rigorous treatment of the entanglement properties of two-mode Gaussian states in atmospheric channels by deriving and analyzing the input-output relations for the corresponding entanglement test. A key feature of such turbulent channels is a nontrivial dependence of the transmitted cont…

[Phys. Rev. A 94, 010302(R)] Published Thu Jul 21, 2016

]]>How can relevant information be extracted from a quantum information source? In many situations, only some part of the total information content produced by an information source is useful. Can one then find an efficient encoding, in the sense of retaining the largest fraction of relevant informatio…

[Phys. Rev. A 94, 012338] Published Thu Jul 21, 2016

]]>One of the most fundamental problems in quantum many-body systems is the identification of a mean field in spontaneous symmetry breaking which is usually made in a heuristic manner. We propose a systematic method of finding a mean field based on the Lie algebra and the dynamical symmetry by introduc…

[Phys. Rev. A 94, 013613] Published Thu Jul 21, 2016

]]>Interactions between many-body atomic systems in optical lattices and light in cavities induce long-range and correlated atomic dynamics beyond the standard Bose-Hubbard model, due to the global nature of the light modes. We characterize these processes, and show that uniting such phenomena with dyn…

[Phys. Rev. A 94, 013614] Published Thu Jul 21, 2016

]]>[Phys. Rev. A 94, 019905] Published Thu Jul 21, 2016

]]>For fermionic fields with nonzero mass, it is shown that the spinor factor of the anticommutation relation between creation and annihilation operators can be justified in a natural way, based on basic properties of Lorentz-invariant inner product in Hilbert space. Furthermore, from the physical poin…

[Phys. Rev. A 94, 012112] Published Wed Jul 20, 2016

]]>Excited-state quantum phase transitions (ESQPTs) are generalizations of quantum phase transitions to excited levels. They are associated with local divergences in the density of states. Here, we investigate how the presence of an ESQPT can be detected from the analysis of the structure of the Hamilt…

[Phys. Rev. A 94, 012113] Published Wed Jul 20, 2016

]]>When two qubits, $A$ and $B$, are in an appropriate state, Alice can remotely steer Bob's system $B$ into different ensembles by making different measurements on $A$. This famous phenomenon is known as quantum steering, or Einstein-Podolsky-Rosen steering. Importantly, quantum steering establishes the corre…

[Phys. Rev. A 94, 012114] Published Wed Jul 20, 2016

]]>Compared to the quantum noise in the measurement of the translational motion of a suspended mirror using laser light, the quantum noise in the measurement of the angular motion of a suspended mirror has not been investigated intensively despite its potential importance. In this article, an expressio…

[Phys. Rev. A 94, 012115] Published Wed Jul 20, 2016

]]>We consider entanglement swapping, a key component of quantum network operations and entanglement distribution. Pure entangled states, which are the desired input to the swapping protocol, are typically mixed by environmental interactions, causing a reduction in their degree of entanglement. Thus an…

[Phys. Rev. A 94, 012336] Published Wed Jul 20, 2016

]]>We report a method that exploits a connection between quantum contextuality and graph theory to reveal any form of quantum contextuality in high-precision experiments. We use this technique to identify a graph which corresponds to an extreme form of quantum contextuality unnoticed before and test it…

[Phys. Rev. A 94, 012337] Published Wed Jul 20, 2016

]]>We report the energy and angular distribution of ejected electrons from $\mathrm{C}{\mathrm{H}}_{4}$ and ${\mathrm{H}}_{2}\mathrm{O}$ molecules impacted by 1 MeV ${\mathrm{H}}^{+},\mathrm{H}{\mathrm{e}}^{+}$, and 650 keV ${\mathrm{N}}^{+}$ ions. Spectra were measured at different observation angles, from 2 to 2000 eV. The obtained absolute double-differential electron-emission cross sections (DDCSs) w…

[Phys. Rev. A 94, 012704] Published Wed Jul 20, 2016

]]>We have studied the ${K}^{-2}V$ process corresponding to simultaneous $K$-shell ionization and $K$-shell excitation in the $\mathrm{C}{\mathrm{O}}_{2}$ molecule. We define these ${K}^{-2}V$ states as super shake-up, at variance with the “conventional” ${K}^{-1}{v}^{-1}V$ shake-up states. While the nature and evolution with photon energy of the conventio…

[Phys. Rev. A 94, 013416] Published Wed Jul 20, 2016

]]>Among many of the nonlinear phenomena induced by strong laser pulses, two of the important processes are the harmonic generation and the creation of neutral atoms in the Rydberg states. We carry out a joint study of the below-threshold high-order-harmonic (BTH) generation and the production of low-l…

[Phys. Rev. A 94, 013417] Published Wed Jul 20, 2016

]]>Electric-field noise is a major source of motional heating in trapped-ion quantum computation. While the influence of trap-electrode geometries on electric-field noise has been studied in patch potential and surface adsorbate models, only smooth surfaces are accounted for by current theory. The effe…

[Phys. Rev. A 94, 013418] Published Wed Jul 20, 2016

]]>A rigorous theoretical framework is developed for a generalized local-frame-transformation theory (GLFT). The GLFT is applicable to the following systems: Rydberg atoms or molecules in an electric field and negative ions in any combination of electric and/or magnetic fields. A first test application…

[Phys. Rev. A 94, 013419] Published Wed Jul 20, 2016

]]>The finite-speed-of-light (FSL) effect is a systematic error in atom gravimeters arising from the time delay due to the propagation of the light. It includes the frequency-chirp-independent part and the frequency-chirp-dependent part, which were not considered completely. The FSL effect in atom grav…

[Phys. Rev. A 94, 013612] Published Wed Jul 20, 2016

]]>We study the localization transition of an atom confined by an external optical lattice in a high-finesse cavity. The atom-cavity coupling yields an effective secondary lattice potential, whose wavelength is incommensurate with the periodicity of the optical lattice. The cavity lattice can induce lo…

[Phys. Rev. A 94, 013839] Published Wed Jul 20, 2016

]]>We introduce a Hermitian generalization of Pauli matrices to higher dimensions which is based on Heisenberg-Weyl operators. The complete set of Heisenberg-Weyl observables allows us to identify a real-valued Bloch vector for an arbitrary density operator in discrete phase space, with a smooth transi…

[Phys. Rev. A 94, 010301(R)] Published Tue Jul 19, 2016

]]>Finding efficient descriptions of how an environment affects a collection of discrete quantum systems would lead to new insights into many areas of modern physics. Markovian, or time-local, methods work well for individual systems, but for groups a question arises: Does system-bath or intersystem co…

[Phys. Rev. A 94, 012110] Published Tue Jul 19, 2016

]]>Monogamy is a fundamental property of Bell nonlocality and contextuality. In this article, we study the $n$-cycle noncontextual inequalities and generalized Clauser-Horne-Shimony-Holt (CHSH) inequalities in detail and find sufficient conditions for those inequalities to hold. According to those condit…

[Phys. Rev. A 94, 012111] Published Tue Jul 19, 2016

]]>We study optomechanical entanglement between an optical cavity field and a movable mirror coupled to a non-Markovian environment. The non-Markovian quantum-state diffusion approach and the non-Markovian master equation are shown to be useful in investigating entanglement generation between the cavit…

[Phys. Rev. A 94, 012334] Published Tue Jul 19, 2016

]]>A family of discrete-time quantum walks (DTQWs) on the line with an exact discrete $\text{U}\left(N\right)$ gauge invariance is introduced. It is shown that the continuous limit of these DTQWs, when it exists, coincides with the dynamics of a Dirac fermion coupled to usual $\text{U}\left(N\right)$ gauge fields in two-dimensional spacetime…

[Phys. Rev. A 94, 012335] Published Tue Jul 19, 2016

]]>Ensemble density-functional theory (eDFT) suffers from the so-called “ghost-interaction” error when approximate exchange-correlation functionals are used. In this work, we present a rigorous ghost-interaction correction (GIC) scheme in the context of range-separated eDFT. The method relies on an exa…

[Phys. Rev. A 94, 012511] Published Tue Jul 19, 2016

]]>The intermonomer three-dimensional potential-energy surface (3D PES) of the thiazyl-hydride–helium (HSN-He) weakly bound molecular system is generated using the explicitly correlated coupled-cluster method with single, double, and perturbative triple excitations. The 3D PES is mapped in Jacobi coord…

[Phys. Rev. A 94, 012512] Published Tue Jul 19, 2016

]]>Photoionization of an atom in the presence of a uniform static electric field provides the unique opportunity to expand and visualize the atomic wave function at a macroscopic scale. In a number of seminal publications dating back to the 1980s, Fabrikant, Demkov, Kondratovich, and Ostrovsky showed t…

[Phys. Rev. A 94, 013414] Published Tue Jul 19, 2016

]]>We present a semiclassical two-step model for strong-field ionization that accounts for path interferences of tunnel-ionized electrons in the ionic potential beyond perturbation theory. Within the framework of a classical trajectory Monte Carlo representation of the phase-space dynamics, the model e…

[Phys. Rev. A 94, 013415] Published Tue Jul 19, 2016

]]>Anyons are particles with fractional statistics that exhibit a nontrivial change in the wave function under an exchange of particles. Anyons can be considered to be a general category of particles that interpolate between fermions and bosons. We determined the position of the critical points of the …

[Phys. Rev. A 94, 013611] Published Tue Jul 19, 2016

]]>An asymmetric resonant cavity can be used to form a path that is much longer than the cavity size. We demonstrate this capability for a deformed microdisk equipped with two linear waveguides, by constructing a multiply reflected periodic orbit that is confined by total internal reflection within the…

[Phys. Rev. A 94, 013831] Published Tue Jul 19, 2016

]]>The coupling of resonant light and surface plasmons in metal layer–coated optical microcavities results in the formation of hybrid photon-plasmon modes. Here, we comprehensively investigate the hybridization mechanism of photon-plasmon modes based on optoplasmonic microtubular cavities. By changing …

[Phys. Rev. A 94, 013832] Published Tue Jul 19, 2016

]]>Quantum features of correlated optical modes define a major aspect of the nonclassicality in quantized radiation fields. However, the phase-sensitive detection of a two-mode light field is restricted to interferometric setups and local intensity measurements. Even the full reconstruction of the quan…

[Phys. Rev. A 94, 013833] Published Tue Jul 19, 2016

]]>We theoretically study the resonance fluorescence spectrum of a three-level quantum emitter coupled to a spherical metallic nanoparticle. We consider the case in which the quantum emitter is driven by a single laser field along one of the optical transitions. We show that the development of the spec…

[Phys. Rev. A 94, 013834] Published Tue Jul 19, 2016

]]>The self-reconfiguration property of a speckle pattern is characterized by having the same autocorrelation profile before and after the obstacle from the point at which the intensity speckle distribution is reestablished; i.e., the speckle pattern becomes homogeneous with no signature of the obstacl…

[Phys. Rev. A 94, 013835] Published Tue Jul 19, 2016

]]>We study both the steady and the dynamic optical response of cold atoms trapped in an optical lattice and driven to the three-level $\mathrm{\Lambda}$ configuration. These atoms are found to exhibit gain without population inversion when an incoherent pump is applied to activate spontaneously generated coherence. Ga…

[Phys. Rev. A 94, 013836] Published Tue Jul 19, 2016

]]>Parity-time ($\mathcal{PT}$) symmetric systems have two distinguished phases, e.g., one with real-energy eigenvalues and the other with complex-conjugate eigenvalues. To enter one phase from the other, it is believed that the system must pass through an exceptional point, which is a non-Hermitian degenerate poi…

[Phys. Rev. A 94, 013837] Published Tue Jul 19, 2016

]]>Sources of photon pairs based on the spontaneous parametric down-conversion process are commonly used for long-distance quantum communication and quantum information processing. The key feature for improving the range of transmission is engineering their spectral properties. Our analysis shows the w…

[Phys. Rev. A 94, 013838] Published Tue Jul 19, 2016

]]>In one-dimensional systems a twisted superfluid phase is found which is induced by a spontaneous breaking of the time-reversal symmetry. Using the density-matrix renormalization group allows us to show that the excitation energy gap closes exponentially causing a quasidegenerate ground state. The tw…

[Phys. Rev. A 94, 011603(R)] Published Mon Jul 18, 2016

]]>A single qubit driven by an appropriate sequence of control pulses can serve as a spectrometer of local noise affecting its energy splitting. We show that by driving and observing two spatially separated qubits, one can reconstruct the spectrum of cross correlations of noises acting at various locat…

[Phys. Rev. A 94, 012109] Published Mon Jul 18, 2016

]]>We present an experimentally feasible scheme to implement holonomic quantum computation in the ultrastrong-coupling regime of light-matter interaction. The large anharmonicity and the ${\mathbb{Z}}_{2}$ symmetry of the quantum Rabi model allow us to build an effective three-level $\mathrm{\Lambda}$-structured artificial atom for qu…

[Phys. Rev. A 94, 012328] Published Mon Jul 18, 2016

]]>In this work, we consider the systematic error of quantum metrology by weak measurements under decoherence. We derive the systematic error of maximum likelihood estimation in general to the first-order approximation of a small deviation in the probability distribution and study the robustness of sta…

[Phys. Rev. A 94, 012329] Published Mon Jul 18, 2016

]]>The correlated emission lasing (CEL) is experimentally demonstrated in harmonic oscillators coupled via a single three-level artificial atom [Phys. Rev. Lett. **115**, 223603 (2015)] in which two-mode entanglement only exists in a certain time period when the harmonic oscillators are resonant with the a…

[Phys. Rev. A 94, 012330] Published Mon Jul 18, 2016

]]>The fully symmetric Gaussian tripartite entangled pure states will not exhibit two-mode Einstein-Podolsky-Rosen (EPR) steering. This means that any two participants cannot share quantum secrets using the security of one-sided device independent quantum key distribution (1SDI-QKD) without involving t…

[Phys. Rev. A 94, 012331] Published Mon Jul 18, 2016

]]>Nonlinear operations are essential for quantum information processing. We propose a way of implementing a class of nonlinear operations by sequential application of conditional gates based on Jaynes-Cummings (JC) interaction and projective measurements. The scheme has many advantages over the previo…

[Phys. Rev. A 94, 012332] Published Mon Jul 18, 2016

]]>Quantum communication without a shared reference frame or the construction of a relational quantum theory requires the notion of a quantum reference frame. We analyze aspects of quantum reference frames associated with noncompact groups, specifically, the group of spatial translations and Galilean b…

[Phys. Rev. A 94, 012333] Published Mon Jul 18, 2016

]]>Using resonant light absorption, random-walk motions of rubidium atoms in nitrogen buffer gas are observed directly. The transmitted light intensity through atomic vapor is measured, and its spectrum is obtained, down to orders of magnitude below the shot-noise level to detect fluctuations caused by…

[Phys. Rev. A 94, 012703] Published Mon Jul 18, 2016

]]>We theoretically study how time- and angle-resolved photoemission spectroscopy can be applied for imaging coherent electron dynamics in molecules. We consider a process in which a pump pulse triggers coherent electronic dynamics in a molecule by creating a valence electron hole. An ultrashort extrem…

[Phys. Rev. A 94, 013412] Published Mon Jul 18, 2016

]]>In a combined experimental and theoretical study we have investigated the ionization of atomic argon upon irradiation with intense soft-x-ray pulses of 105 eV photon energy from the free-electron laser FLASH. The measured ion yields show charge states up to ${\mathrm{Ar}}^{7+}$. The comparison with the theoretical …

[Phys. Rev. A 94, 013413] Published Mon Jul 18, 2016

]]>Interacting Fermi systems in the strongly correlated regime play a fundamental role in many areas of physics and are of particular interest to the condensed matter community. Though weakly interacting fermions are understood, strongly correlated fermions are difficult to describe theoretically as th…

[Phys. Rev. A 94, 013610] Published Mon Jul 18, 2016

]]>We examine the performance of a nonlinear fiber gyroscope for improved signal detection beating the quantum limits of its linear counterparts. The performance is examined when the nonlinear gyroscope is illuminated by practical field states, such as coherent and quadrature squeezed states. This is c…

[Phys. Rev. A 94, 013830] Published Mon Jul 18, 2016

]]>I calculate the mixed three-tangle ${\tau}_{3}\left[\rho \right]$ for the reduced density matrices of the four-qubit representant states found in Phys. Rev. A **65**, 052112 (2002). In most of the cases, the convex roof is obtained, except for one class, where I provide with an upper bound, which is assumed to be very close to …

[Phys. Rev. A 94, 012323] Published Fri Jul 15, 2016

]]>The sensitivity of classical and quantum sensing is impaired in a noisy environment. Thus, one of the main challenges facing sensing protocols is to reduce the noise while preserving the signal. State-of-the-art quantum sensing protocols that rely on dynamical decoupling achieve this goal under the …

[Phys. Rev. A 94, 012324] Published Fri Jul 15, 2016

]]>We identify and study a security loophole in continuous-variable quantum key distribution (CVQKD) implementations, related to the imperfect linearity of the homodyne detector. By exploiting this loophole, we propose an active side-channel attack on the Gaussian-modulated coherent-state CVQKD protoco…

[Phys. Rev. A 94, 012325] Published Fri Jul 15, 2016

]]>We define the non–coherence-generating channel as the completely positive trace-preserving map which does not generate quantum coherence from an incoherent state. The incoherent operations are the strict subset of the non–coherence-generating channels. Although the relative entropy of coherence is m…

[Phys. Rev. A 94, 012326] Published Fri Jul 15, 2016

]]>We study the propagation of different types of correlations through a quantum bus formed by a chain of coupled harmonic oscillators. This includes steering, entanglement, mutual information, quantum discord, and Bell-like nonlocality. The whole system consists of the quantum bus (propagation medium)…

[Phys. Rev. A 94, 012327] Published Fri Jul 15, 2016

]]>We propose a technique to fully characterize the temporal structure of extreme ultraviolet pulses by ionizing a bound coherent electronic wave packet. The influence of the dipole phase, which is the main obstacle for state-of-the-art pulse characterization schemes, can be eliminated by angle integra…

[Phys. Rev. A 94, 013411] Published Fri Jul 15, 2016

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