We study the finite time entanglement dynamics between two dark-soliton qubits due to quantum fluctuations in quasi-one-dimensional Bose-Einstein condensates. Recently, dark solitons are proved to be an appealing platform for qubits due to their appreciably long lifetime. We explore the entanglement...

[Phys. Rev. A 98, 022319] Published Thu Aug 16, 2018

]]>We present an analytical and numerical analysis of the particle creation in a cavity ended with two superconducting quantum interference devices, both subjected to time-dependent magnetic fields. In the linear and lossless regime, the problem can be modeled by a free quantum field in $1+1$ dimensions,...

[Phys. Rev. A 98, 022512] Published Thu Aug 16, 2018

]]>The SU(1,1) interferometer was originally conceived as a Mach-Zehnder interferometer with the beam splitters replaced by parametric amplifiers. The parametric amplifiers produce states with correlations that result in enhanced phase sensitivity. $F=1$ spinor Bose-Einstein condensates (BECs) can serve ...

[Phys. Rev. A 98, 023620] Published Thu Aug 16, 2018

]]>We show how one can prepare and detect entanglement and Einstein-Podolsky-Rosen (EPR) steering between two distinguishable groups (modes) of atoms in a Bose-Einstein condensate (BEC) atom interferometer. Our paper extends previous work that developed criteria for two-mode entanglement and EPR steeri...

[Phys. Rev. A 98, 022120] Published Wed Aug 15, 2018

]]>We demonstrate under which conditions a violation of the charge-parity (*CP*) symmetry in molecules will manifest itself in the Casimir-Polder interaction of these with a magnetodielectric surface. Charge-parity violation induces a specific electric-magnetic cross polarizability in a molecule that is ...

[Phys. Rev. A 98, 022510] Published Wed Aug 15, 2018

]]>Properties of a class of traceless Hamiltonians are employed to cancel spin-dependent contributions and systematic shifts to molecular transition frequencies. The examples of H${}_{2}^{+}$ and HD${}^{+}$ molecular ions are shown to demonstrate the cancellations of spin structure, electric quadrupole shift, the Zeeman shift, and partially the Stark shift.

[Phys. Rev. A 98, 022511] Published Wed Aug 15, 2018

]]>We present molecular above-threshold ionization (ATI) by multiple-frequency circularly polarized laser pulses. Simulations are performed on aligned ${\mathrm{H}}_{2}{}^{+}$ by numerically solving corresponding time-dependent Schrödinger equations. Molecular ATI spectra show maximum cutoff and multiple ionization traject...

[Phys. Rev. A 98, 023413] Published Wed Aug 15, 2018

]]>We investigate the physics of a gas of ultracold atoms coupled to three single-mode optical cavities and transversely pumped with a laser. Recent work has demonstrated that, for two cavities, the ${\mathbb{Z}}_{2}$ symmetries of each cavity can be combined into a global U(1) symmetry [J. Léonard *et al.*, Nature (Lon...

[Phys. Rev. A 98, 023617] Published Wed Aug 15, 2018

]]>Quantized vortices have been observed in a variety of superfluid systems, from ${}^{4}\mathrm{He}$ to condensates of alkali-metal bosons and ultracold Fermi gases along the BEC-BCS crossover. In this article we study the stability of singly quantized vortex lines in dilute dipolar self-bound droplets. We first disc...

[Phys. Rev. A 98, 023618] Published Wed Aug 15, 2018

]]>The variational JWKB method is used to determine experimentally accessible macroscopic quantum tunneling regimes of quasibound Bose-Einstein condensates in two quasi-one-dimensional trap configurations. The potentials can be created by magnetic and optical traps: a symmetric trap from two offset Gau...

[Phys. Rev. A 98, 023619] Published Wed Aug 15, 2018

]]>We design a single microwave photon switch through a one-dimensional waveguide coupled with a side Jaynes-Cummings system, namely, a single-mode cavity with an embedded Rydberg atom ${}^{87}\mathrm{Rb}$. Since the energy spectra of the ${}^{87}\mathrm{Rb}$ atom depend on the electrostatic field, the ${}^{87}\mathrm{Rb}$ atom can couple with the c...

[Phys. Rev. A 98, 023830] Published Wed Aug 15, 2018

]]>We report experiments on propagation of scalar and vector optical beams through random phase screens mimicking turbulence and show that the intensity profile of the beam containing a C-point polarization singularity shows maximally robust behavior. This observation is explained in terms of the polar...

[Phys. Rev. A 98, 023831] Published Wed Aug 15, 2018

]]>The capture and confinement of a large and pure sample of anions into an ion trap is challenging due to the fragile nature of these weakly bound atomic systems. We present the results of an experimental study using ${\mathrm{Au}}^{-}$ in which anions from a keV-energy continuous beam were loaded into a cylindrical ...

[Phys. Rev. A 98, 021402(R)] Published Tue Aug 14, 2018

]]>The Jaynes-Cummings system is one of the most fundamental models of how light and matter interact. When driving the system with a coherent state (e.g., laser light), it is often assumed that whether the light couples through the cavity or atom plays an important role in determining the dynamics of t...

[Phys. Rev. A 98, 021802(R)] Published Tue Aug 14, 2018

]]>We discuss quantum optimal control of Bose-Einstein condensates trapped in magnetic microtraps. The objective is to transfer a condensate from the ground state to the first-excited state. This type of control problem is typically solved using derivative-based methods in a high-dimensional control sp...

[Phys. Rev. A 98, 022119] Published Tue Aug 14, 2018

]]>Local and intrinsic quantum coherence, as two contributions of total quantum coherence, have been introduced by Radhakrishnan *et al.* [C. Radhakrishnan, M. Parthasarathy, S. Jambulingam, and T. Byrnes, Phys. Rev. Lett. **116**, 150504 (2016)]. In the present work we study the property of local, intrinsic...

[Phys. Rev. A 98, 022317] Published Tue Aug 14, 2018

]]>Entangled multiqubit states are an essential resource for quantum information and computation. Solid-state emitters can mediate interactions between subsequently emitted photons via their spin, thus offering a route towards generating entangled multiphoton states. However, existing schemes typically...

[Phys. Rev. A 98, 022318] Published Tue Aug 14, 2018

]]>Singly ionized lutetium has a number of fortuitous properties well suited for a design of an optical clock and corresponding applications. In this work, we study ${\mathrm{Lu}}^{+}$ properties relevant to a development of the clock using the relativistic high-precision method combining configuration interaction and...

[Phys. Rev. A 98, 022509] Published Tue Aug 14, 2018

]]>We propose to correct the ionization factor in the quantitative rescattering (QRS) theory for a higher precision calculation of macroscopic high harmonic generation (HHG) in a gaseous medium. Compared to the first-order strong-field approximation (SFA-1) and the Ammosov-Delone-Krainov (ADK) ionizati...

[Phys. Rev. A 98, 023411] Published Tue Aug 14, 2018

]]>Nondipole effects in the atomic dynamic interference are investigated by numerically solving the time-dependent Schrödinger equation (TDSE) of hydrogen. It is found that the inclusion of nondipole corrections in the TDSE can induce momentum shifts of photoelectrons in the opposite direction of the l...

[Phys. Rev. A 98, 023412] Published Tue Aug 14, 2018

]]>A first-order type phase transition between Mott lobes has been reported in Phys. Rev. Lett. **109**, 135302 (2012) for a two-dimensional Bose-Hubbard model in the presence of an attractive three-body interaction. We revisit the scenario in systems of ultracold bosons both in one- and two-dimensional la...

[Phys. Rev. A 98, 023615] Published Tue Aug 14, 2018

]]>The two-component Fermi gas with contact attractive interactions between different spin components can be described by the Yang-Gaudin model. Applying the Bethe ansatz approach, one finds analytical formulas for the system eigenstates that are uniquely parametrized by the solutions of the correspond...

[Phys. Rev. A 98, 023616] Published Tue Aug 14, 2018

]]>We experimentally and theoretically study propagation of 80-ns Gaussian-like probe pulses in hot potassium vapor under conditions of four-wave mixing (FWM). The atomic scheme for FWM is off-resonant, double-$\mathrm{\Lambda}$ atomic scheme, with pump and probe photons, mediated in the K vapor, generating new probe a...

[Phys. Rev. A 98, 023829] Published Tue Aug 14, 2018

]]>We show that dynamical quantum phase transitions (DQPTs) in the quench dynamics of two-dimensional topological systems can be characterized by a dynamical topological invariant defined along an appropriately chosen closed contour in momentum space. Such a dynamical topological invariant reflects the...

[Phys. Rev. A 98, 021601(R)] Published Mon Aug 13, 2018

]]>The most general class of nonlocality criteria for $N$-partite $d$-chotomic systems with $k$ number of measurement settings is derived under the constraint of measurement symmetries. It is the complete characterization of the multipartite nonlocality when the correlation is assumed to be symmetric under t...

[Phys. Rev. A 98, 022116] Published Mon Aug 13, 2018

]]>We investigate the scattering properties of a parity-time-antisymmetric non-Hermitian system. The parity-time-antisymmetric scattering center possesses imaginary nearest-neighbor hoppings and real on-site potentials; it has been experimentally realized through dissipative coupling and frequency detu...

[Phys. Rev. A 98, 022117] Published Mon Aug 13, 2018

]]>In the Unruh effect an observer with constant acceleration perceives the quantum vacuum as thermal radiation. The Unruh effect has been believed to be a pure quantum phenomenon, but here we show theoretically how the effect arises from the correlation of noise, regardless of whether this noise is qu...

[Phys. Rev. A 98, 022118] Published Mon Aug 13, 2018

]]>Entanglement distillation is the process of concentrating entanglement from a given quantum state. We present a technique for distillation of bipartite polarization entanglement using interferometry. This technique can be optimized to extract maximal entanglement from any pure or mixed entangled sta...

[Phys. Rev. A 98, 022313] Published Mon Aug 13, 2018

]]>Reverse annealing is a variant of quantum annealing that starts from a given classical configuration of spins (qubits). In contrast to the conventional formulation, where one starts from a uniform superposition of all possible states (classical configurations), quantum fluctuations are first increas...

[Phys. Rev. A 98, 022314] Published Mon Aug 13, 2018

]]>The adiabatic theorem of quantum mechanics states that the error between an instantaneous eigenstate of a time-dependent Hamiltonian and the state given by quantum evolution of duration $\tau $ is upper bounded by $C/\tau $ for some positive constant $C$. It has been known for decades that this error can be reduc...

[Phys. Rev. A 98, 022315] Published Mon Aug 13, 2018

]]>Two main obstacles for observing quantum advantage in noisy intermediate-scale quantum computers (NISQ) are the finite-precision effects due to control errors, or disorders, and decoherence effects due to thermal fluctuations. It has been shown that dissipative quantum computation is possible in the...

[Phys. Rev. A 98, 022316] Published Mon Aug 13, 2018

]]>Electron interactions with the nuclear-spin-dependent (NSD) parity-nonconserving (PNC) anapole moment are strongly enhanced within heteronuclear diatomic molecules. A low-energy optical rotation experiment is being proposed with the aim of observing NSD PNC interactions in HgH. Based on the relativi...

[Phys. Rev. A 98, 022508] Published Mon Aug 13, 2018

]]>We extend the semiclassical two-step model [Phys. Rev. A **94**, 013415 (2016)] to include a multielectron polarization-induced dipole potential. Using this model we investigate the imprints of multielectron effects in the momentum distributions of photoelectrons ionized by a linearly polarized laser pu...

[Phys. Rev. A 98, 023406] Published Mon Aug 13, 2018

]]>We investigate theoretically the above-threshold ionization (ATI) of localized atomic targets by intense few-cycle Bessel pulses that carry orbital angular momentum (OAM), known also as twisted light. More specifically, we use the strong-field approximation (SFA) to compute the photoelectron energy ...

[Phys. Rev. A 98, 023407] Published Mon Aug 13, 2018

]]>We demonstrate that a bichromatic standing-wave laser field can exert a significantly larger force on a molecule than ordinary radiation pressure. Our experiment measures the deflection of a pulsed supersonic beam of CaF molecules by a two-frequency laser field detuned symmetrically about resonance ...

[Phys. Rev. A 98, 023408] Published Mon Aug 13, 2018

]]>The calculation of partial two-photon ionization cross sections in the above-threshold energy region is discussed in the framework of exterior complex scaling. It is shown that with a minor modification of the usual procedure, which is based on the calculation of the outgoing partial waves of the se...

[Phys. Rev. A 98, 023409] Published Mon Aug 13, 2018

]]>Our investigation considers the amended strong-field approximation (SFA) ionization of rare-gas atoms in a strong laser field accompanied by excitation of the atom due to laser-induced recollision. This process can be viewed as inelastic above-threshold ionization and corresponds to the recollision-...

[Phys. Rev. A 98, 023410] Published Mon Aug 13, 2018

]]>Spontaneous breaking of continuous time translation symmetry into a discrete one is related to time crystal formation. While the phenomenon is not possible in the ground state of a time-independent many-body system, it can occur in an excited eigenstate. Here, we concentrate on bosons on a ring with...

[Phys. Rev. A 98, 023612] Published Mon Aug 13, 2018

]]>We develop a highly efficient method to numerically simulate thermal fluctuations and correlations in nonrelativistic continuous bosonic one-dimensional systems. The method is suitable for arbitrary local interactions as long as the system remains dynamically stable. We start by proving the equivale...

[Phys. Rev. A 98, 023613] Published Mon Aug 13, 2018

]]>Recent experiments on a one-dimensional chain of trapped alkali-metal atoms [Bernien *et al.*, Nature (London) **551**, 579 (2017)] have observed a quantum transition associated with the onset of period-3 ordering of pumped Rydberg states. This spontaneous ${\mathbb{Z}}_{3}$ symmetry breaking is described by a constrain...

[Phys. Rev. A 98, 023614] Published Mon Aug 13, 2018

]]>Researchers have entangled six modes of a laser cavity—a record number for such a device.

[Phys. Rev. A 98, 023823] Published Mon Aug 13, 2018

]]>We have studied manifestation of optical activity for higher-order modes that propagate in optical fibers with multihelical distribution of the refractive index profile. We have shown that due to form-induced intermodal coupling between the fundamental modes and the higher-order modes the hybrid mod...

[Phys. Rev. A 98, 023824] Published Mon Aug 13, 2018

]]>Optical analog experiments have captured a lot of interest in recent years by offering a strategy to test theoretical models and concepts that would be otherwise untestable. The approach relies on the similarity between the mathematical model for light propagation in nonlinear optical media and the ...

[Phys. Rev. A 98, 023825] Published Mon Aug 13, 2018

]]>The classification of band structures by topological invariants provides a powerful tool for understanding phenomena such as the quantum Hall effect. This classification was originally developed in the context of electrons but can also be applied to photonic crystals. In this paper we study the topo...

[Phys. Rev. A 98, 023826] Published Mon Aug 13, 2018

]]>We report the formation of bound states in the continuum in a whispering gallery resonator coupled to a one-dimensional waveguide. We find that an incident photon wave packet is partially stored in the bound state in the continuum due to a roughness-induced symmetry breaking. We discuss quantum inte...

[Phys. Rev. A 98, 023827] Published Mon Aug 13, 2018

]]>It has recently been shown [Rossi *et al.*, Phys. Rev. Lett. **119**, 123603 (2017); Phys. Rev. Lett. **120**, 073601 (2018)] that feedback-controlled in-loop light can be used to enhance the efficiency of optomechanical systems. We analyze the theoretical ground at the basis of this approach and explore its...

[Phys. Rev. A 98, 023828] Published Mon Aug 13, 2018

]]>The challenges of entanglement detection lead to the development of several entanglement measures and criteria. Here a special type of measurement is used to attest entanglement in a stronger way, i.e. it catches forms that are missed by other criteria and is effective in a single-shot fashion.

[Phys. Rev. A 98, 022309] Published Fri Aug 10, 2018

]]>Quantum repeater networks are a fundamental of any future quantum internet and long-distance quantum communications. The entangled quantum nodes can communicate through several different levels of entanglement, leading to a heterogeneous, multilevel network structure. The level of entanglement betwe...

[Phys. Rev. A 98, 022310] Published Fri Aug 10, 2018

]]>We consider the problem of one-sided device-independent self-testing of any pure entangled two-qubit state based on steering inequalities which certify the presence of quantum steering. In particular, we note that in the 2-2-2 steering scenario (involving two parties, two measurement settings per pa...

[Phys. Rev. A 98, 022311] Published Fri Aug 10, 2018

]]>By local measurements on party $A$ of a system $\mathit{AB}$ and classical communication between its two parties, one can achieve a nonlocal advantage of quantum coherence (NAQC) on party $B$. For the ${l}_{1}$ norm of coherence and the relative entropy of coherence, we generalized the framework of NAQC for two qubits an...

[Phys. Rev. A 98, 022312] Published Fri Aug 10, 2018

]]>The original formulation [M. Piris, Phys. Rev. Lett. **119**, 063002 (2017)] of the natural-orbital-functional second-order-Møller-Plesset (NOF-MP2) method is based on the MP2 that uses the canonical Hartree-Fock molecular orbitals. The current work presents a reformulation of the dynamic energy correct...

[Phys. Rev. A 98, 022504] Published Fri Aug 10, 2018

]]>We present high-resolution data of the single-excitation spectrum of protactinium, reaching slightly beyond the first-ionization threshold. Within this work, more than 1500 energy levels are recorded in different excitation energy ranges below $50\phantom{\rule{0.16em}{0ex}}000\phantom{\rule{4pt}{0ex}}{\mathrm{cm}}^{-1}$. Our experimental results show that the tabula...

[Phys. Rev. A 98, 022505] Published Fri Aug 10, 2018

]]>Recently, spectroscopic investigations of the protactinium atom applying resonant laser ionization spectroscopy revealed high-resolution data of the single-excitation spectrum of protactinium, reaching slightly beyond the first ionization potential [P. Naubereit *et al.*, preceding paper, Phys. Rev. ...

[Phys. Rev. A 98, 022506] Published Fri Aug 10, 2018

]]>The role of electron correlation in the hyperfine structure of alkali metals and alkaline earth metal monopositive ions in their ground electronic configuration is investigated using the *Z*-vector method in a relativistic coupled-cluster regime within the singles and doubles approximation. The system...

[Phys. Rev. A 98, 022507] Published Fri Aug 10, 2018

]]>Simultaneous ionization and excitation of helium by electron impact is studied through ejected electron angle integrated double-differential cross sections (DDCSs) as a function of ionized electron energy using the four-body distorted wave model. Results are presented for different alignments of the...

[Phys. Rev. A 98, 022703] Published Fri Aug 10, 2018

]]>We derive a variation equation for a time-dependent effective potential that is local both in time and in space and show that this potential generates and propagates spin orbitals with which a many-particle, time-dependent, multiconfigurational wave function $\mathrm{\Psi}\left(t\right)$ is constructed. Within this approach...

[Phys. Rev. A 98, 023405] Published Fri Aug 10, 2018

]]>Based on the two-dimensional mean-field equations for pancake-shaped dipolar Bose-Einstein condensates in a rotating frame, for both attractive and repulsive dipole-dipole interaction (DDI) as well as arbitrary polarization direction, we study the profiles of the single vortex state and show how the...

[Phys. Rev. A 98, 023610] Published Fri Aug 10, 2018

]]>By employing the equivalent of a knife-edge measurement for matter waves, we are able to characterize ultralow-momentum widths. We measure a momentum width corresponding to an effective temperature of $0.9\phantom{\rule{0.28em}{0ex}}\pm \phantom{\rule{0.28em}{0ex}}0.2$ nK, limited only by our cooling performance. To achieve similar resolution using standard m...

[Phys. Rev. A 98, 023611] Published Fri Aug 10, 2018

]]>We present a systematic theoretical investigation of second-harmonic generation (SHG) in a subwavelength lithium niobate (LN) single-crystal thin-film waveguide with birefringence in permittivity and refractive index and strong anisotropy in the nonlinear susceptibility ${\chi}^{\left(2\right)}$. In a macroscopic birefr...

[Phys. Rev. A 98, 023820] Published Fri Aug 10, 2018

]]>We discuss level splitting and sideband transitions induced by a modulated coupling between a superconducting quantum circuit and a nanomechanical resonator. First, we show how to achieve an unconventional time-dependent longitudinal coupling between a flux (transmon) qubit and the resonator. Consid...

[Phys. Rev. A 98, 023821] Published Fri Aug 10, 2018

]]>The nonlinear interaction of two temporally separated solitons inside optical fibers has been studied in the scalar case in which both solitons remain linearly polarized during their mutual interaction. Here we consider two arbitrarily polarized vector solitons inside birefringent optical fibers whe...

[Phys. Rev. A 98, 023822] Published Fri Aug 10, 2018

]]>The correlations of certain entangled quantum states can be fully reproduced via a local model. We discuss in detail the practical implementation of an algorithm for constructing local models for entangled states, recently introduced by Hirsch *et al.* [Phys. Rev. Lett. **117**, 190402 (2016)] and Cavalca...

[Phys. Rev. A 98, 022115] Published Thu Aug 09, 2018

]]>The Casimir force between two parallel thick plates, one perfectly dielectric, the other purely magnetic, was calculated long ago by Boyer [T. H. Boyer, Phys. Rev. A **9**, 2078 (1974)]. Its most characteristic property is that it is repulsive. The problem of this repulsive behavior is actually delicate...

[Phys. Rev. A 98, 022503] Published Thu Aug 09, 2018

]]>A combined experimental and theoretical study of superelastic electron collisions from laser-aligned magnesium atoms for a range of collision energies from 35 to 55 eV is presented. ${}^{24}\mathrm{Mg}$ atoms were excited from the $3\phantom{\rule{0.16em}{0ex}}{}^{1}S_{0}$ ground state to the $3\phantom{\rule{0.16em}{0ex}}{}^{1}P_{1}$ excited state using continuous-wave linearly polarized ...

[Phys. Rev. A 98, 022702] Published Thu Aug 09, 2018

]]>In the usual optomechanical cooling, even if the system has no thermal component, it still has a quantum limit—known as the quantum backaction limit (QBL)—on the minimum phonon number related to shot noise. By studying the side-band cooling regime in optomechanical systems (OMSs), we find that the c...

[Phys. Rev. A 98, 023816] Published Thu Aug 09, 2018

]]>We calculate signals of real photon-photon scattering in the collision of three laser pulses. Taking goal parameters from the Station of Extreme Light at the upcoming Shanghai Coherent Light Source, we consider two scenarios: (i) the collision of three optical pulses; (ii) the collision of an XFEL w...

[Phys. Rev. A 98, 023817] Published Thu Aug 09, 2018

]]>The defining characteristic of an exceptional point (EP) in the parameter space of a family of operators is that, upon encircling the EP, eigenstates are permuted. When one encircles multiple EPs, the question arises how to properly compose the effects of the individual EPs. This was thought to be a...

[Phys. Rev. A 98, 023818] Published Thu Aug 09, 2018

]]>Quantum control of phonons has become a focus of attention for developing quantum technologies. Here, we present a proposal to realize phonon blockade in a quadratically coupled optomechanical system, where a strong nonlinear interaction between photons and phonons can be induced by an external fiel...

[Phys. Rev. A 98, 023819] Published Thu Aug 09, 2018

]]>We experimentally investigate the unitarity-limited behavior of the three-body loss near a $p$-wave Feshbach resonance in a single-component Fermi gas of ${}^{6}\mathrm{Li}$ atoms. At the unitarity limit, the three-body loss coefficient ${L}_{3}$ exhibits universality in the sense that it is independent of the interaction s...

[Phys. Rev. A 98, 020702(R)] Published Wed Aug 08, 2018

]]>The interaction of a two-level system (TLS) with a single bosonic mode (BM) is one of the most fundamental processes in quantum optics. Microscopically, it is described by the quantum Rabi model (QRM). Here we propose a versatile implementation of this model based on single trapped cold atoms. Assum...

[Phys. Rev. A 98, 021801(R)] Published Wed Aug 08, 2018

]]>It has long been recognized that certain quantum correlations are incompatible with a particular assumption about classical causal structure. Given a causal structure of unknown classicality, the presence of such correlations certifies the nonclassical nature of the causal structure in a device-inde...

[Phys. Rev. A 98, 022113] Published Wed Aug 08, 2018

]]>We investigate the qubit in the hierarchical environment where the first layer is just one lossy cavity while the second layer is the $N$-coupled lossy cavities. In the weak-coupling regime between the qubit and the first-layer environment, the dynamics crossovers from Markovian to non-Markovian and f...

[Phys. Rev. A 98, 022114] Published Wed Aug 08, 2018

]]>We studied the change of the nonlocal correlation of the entanglement in Rindler space-time by showing that the Unruh effect can be interpreted as a noisy quantum channel having a complete positive and trace preserving map with an “operator sum representation.” It is shown that the entanglement fide...

[Phys. Rev. A 98, 022308] Published Wed Aug 08, 2018

]]>We study the prospects of using transitions from the ytterbium ground state to metastable states ${}^{3}P_{2}^{\mathrm{o}}$ at $E=19\phantom{\rule{0.16em}{0ex}}710.388\phantom{\rule{4pt}{0ex}}{\mathrm{cm}}^{-1}$ and $4{f}^{13}5d6{s}^{2}\phantom{\rule{4pt}{0ex}}(J=2)$ at $E=23\phantom{\rule{0.16em}{0ex}}188.518\phantom{\rule{4pt}{0ex}}{\mathrm{cm}}^{-1}$ as clock transitions in an optical lattice clock. Having more than one clock transition in Yb could benefit the search for new physics beyond...

[Phys. Rev. A 98, 022501] Published Wed Aug 08, 2018

]]>We study far- and near-field magnetic and electric multipole moments induced in the ground state of the Dirac one-electron atom placed in a weak ${2}^{L}$-pole magnetostatic field. The analysis is carried out within the framework of the first-order Rayleigh-Schrödinger perturbation theory, with the use of ...

[Phys. Rev. A 98, 022502] Published Wed Aug 08, 2018

]]>Atomic or molecular assemblies irradiated with intense hard x-ray pulses, such as those emitted from x-ray free-electron lasers (XFELs), are subject to a strong ionization, which also releases electrons from atomic inner shells. The resulting core-hole states relax via various channels, including fl...

[Phys. Rev. A 98, 022701] Published Wed Aug 08, 2018

]]>Synthetic fields applied to ultracold quantum gases can realize topological phases that transcend conventional Bose and Fermi-liquid paradigms. Raman laser beams in particular are under scrutiny as a route to create synthetic fields in neutral gases to mimic ordinary magnetic and electric fields act...

[Phys. Rev. A 98, 023609] Published Wed Aug 08, 2018

]]>The process of coherent x-ray emission by an ultrarelativistic electron crossing a system of two targets, thick amorphous upstream and ultrathin crystalline downstream, is considered. It is shown that transformation of the electromagnetic field around the particle after its emission from the upstrea...

[Phys. Rev. A 98, 023813] Published Wed Aug 08, 2018

]]>We theoretically investigate the transport properties of a weak coherent input field scattered by an ensemble of $\mathrm{\Lambda}$-type atoms coupled to a one-dimensional photonic crystal waveguide. In our model, the atoms are randomly located in the lattice along the crystal axis. We analyze the transmission spect...

[Phys. Rev. A 98, 023814] Published Wed Aug 08, 2018

]]>We propose a method to deterministically prepare a desired quantum state in a one-dimensional (1D) continuum by a shaped photon pulse. This method is based on time reversal of the quantum emission process. We show that the desired quantum state such as a Dicke or timed Dicke state can be successfull...

[Phys. Rev. A 98, 023815] Published Wed Aug 08, 2018

]]>We propose that the ground term transition, $2{p}^{5}\phantom{\rule{0.16em}{0ex}}{}^{2}P_{3/2}-{}^{2}P_{1/2}$, for ions in the F-like isoelectronic sequence could be used to accurately test current methods to compute Breit and quantum-electrodynamic (QED) effects. These systems are of interest since correlation is small due to what we will label Lay...

[Phys. Rev. A 98, 020502(R)] Published Tue Aug 07, 2018

]]>Interatomic Coulombic electron capture (ICEC) is an environment-assisted process in which a free electron can efficiently attach to an ion, atom or molecule by transferring the excess energy to a neighboring species. Absolute cross sections are necessary to evaluate the relative importance of this p...

[Phys. Rev. A 98, 020701(R)] Published Tue Aug 07, 2018

]]>When a photon is detected after passing through an interferometer one might wonder which path it took, and a meaningful answer can only be given if one has the means of monitoring the photon's whereabouts. We report the realization of a single-photon experiment for a two-path interferometer with pat...

[Phys. Rev. A 98, 022110] Published Tue Aug 07, 2018

]]>The stochastic dynamics of a quantum system driven by $N$ statistically independent random sudden quenches in a fixed time interval is studied. We reveal that with increasing $N$ the system approaches a deterministic limit, indicating self-averaging with respect to its temporal unitary evolution. This p...

[Phys. Rev. A 98, 022111] Published Tue Aug 07, 2018

]]>Contextuality is the leading notion of nonclassicality for a single system. However, an experimental demonstration requires finding procedures that are operationally equivalent, which might seem impossible to achieve exactly. Here I focus on the simplest nontrivial case, four preparations and two to...

[Phys. Rev. A 98, 022112] Published Tue Aug 07, 2018

]]>We study the performance of quantum error correction (QEC) on a system undergoing open-system (OS) dynamics. The noise on the system originates from a joint quantum channel on the system-bath composite, a framework that includes and interpolates between the commonly used system-only quantum noise ch...

[Phys. Rev. A 98, 022307] Published Tue Aug 07, 2018

]]>We present a rigorous study of momentum distribution and $p$-wave contacts of one-dimensional spinless Fermi gases with an attractive $p$-wave interaction. Using the Bethe ansatz wave function, we calculate analytically the high-momentum tail and show that the leading ($\sim 1/{p}^{2}$) and sub-leading terms ($\sim 1/{p}^{\mathrm{...}}$

[Phys. Rev. A 98, 023605] Published Tue Aug 07, 2018

]]>Quantum Hall (QH) states of two-dimensional (2D) single-layer optical lattices are examined using the Bose-Hubbard model (BHM) in the presence of an artificial gauge field. We study the QH states of both the homogeneous and inhomogeneous systems. For the homogeneous case, we use cluster Gutzwiller m...

[Phys. Rev. A 98, 023606] Published Tue Aug 07, 2018

]]>We study the criticality of a long-range quantum ferromagnetic Ising chain with algebraically decaying interactions $1/{r}^{\alpha}$ via the fidelity susceptibility based on the exact diagonalization and the density-matrix renormalization-group techniques. We find that critical exponents change monotonically fr...

[Phys. Rev. A 98, 023607] Published Tue Aug 07, 2018

]]>We determine the evolution of a cluster of quantum vortices initially placed at the center of a larger vortex-free region. We find that the cluster spreads out spatially. This spreading motion consists of two effects: the rapid evaporation of vortex dipoles from the cluster and the slow expansion of...

[Phys. Rev. A 98, 023608] Published Tue Aug 07, 2018

]]>The reflectance of graphene is investigated in the framework of the Dirac model with account of its realistic properties, such as nonzero chemical potential and band gap, at any temperature. For this purpose, the exact reflection coefficients of the electromagnetic waves on a graphene sheet expresse...

[Phys. Rev. A 98, 023809] Published Tue Aug 07, 2018

]]>We demonstrate that reorientational spatial solitons can curve when propagating in a medium with engineered walk-off along the direction of propagation. In this regard, we employ nematic liquid crystals with molecular anchoring defined by electron-beam lithography and optic axis distribution modulat...

[Phys. Rev. A 98, 023810] Published Tue Aug 07, 2018

]]>We explore the coherent dynamics of a three-level $\mathsf{V}$-type system interacting with a thermal bath in the regime where thermal excitation occurs much faster than spontaneous decay. We present analytic solutions of the Bloch-Redfield quantum master equations, which show that strong incoherent pumping ca...

[Phys. Rev. A 98, 023811] Published Tue Aug 07, 2018

]]>Spatial coherence quantifies spatial field correlations and is one of the fundamental properties of light. Here we investigate the spatial coherence of highly multimode lasers in the regime of short timescales. Counterintuitively, we show that in this regime, the temporal (longitudinal) modes play a...

[Phys. Rev. A 98, 023812] Published Tue Aug 07, 2018

]]>Hafnium is the last transition-metal element with an undetermined electron affinity. Using a slow-electron velocity-map imaging spectrometer equipped with a cold ion trap, the electron affinity of hafnium atoms is measured to be $1436\left(5\right)\phantom{\rule{0.16em}{0ex}}\mathrm{c}{\mathrm{m}}^{-1}$ or 0.1780(6) eV. The cold ion trap employed in the present ...

[Phys. Rev. A 98, 020501(R)] Published Mon Aug 06, 2018

]]>Quantum coherence can be used to infer the presence of a detector without triggering it. Here we point out that, according to quantum mechanics, such interaction-free measurements cannot be perfect, i.e., in a single-shot experiment one has strictly positive probability to activate the detector. We ...

[Phys. Rev. A 98, 022108] Published Mon Aug 06, 2018

]]>We experimentally and theoretically investigate the nonequilibrium phase structure of a well-controlled driven-dissipative quantum spin system governed by the interplay of coherent driving, spontaneous decay, and long-range spin-spin interactions. We discover that the rate of population loss provide...

[Phys. Rev. A 98, 022109] Published Mon Aug 06, 2018

]]>High-fidelity qubit measurements play a crucial role in quantum computation, communication, and metrology. In recent experiments, it has been shown that readout fidelity can be improved by performing repeated quantum nondemolition (QND) readouts of a qubit's state through an ancilla. For a qubit enc...

[Phys. Rev. A 98, 022305] Published Mon Aug 06, 2018

]]>Both coherence and entanglement stem from the superposition principle, capture quantumness of a physical system, and play a central role in quantum physics. In a multipartite quantum system, coherence and quantum correlations are closely connected. In particular, it has been established that quantum...

[Phys. Rev. A 98, 022306] Published Mon Aug 06, 2018

]]>The complex Kohn variational method is extended to compute light-driven electronic transitions between continuum wave functions in atomic and molecular systems. This development enables the study of multiphoton processes in the perturbative regime for arbitrary light polarization. As a proof of prin...

[Phys. Rev. A 98, 023403] Published Mon Aug 06, 2018

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