We consider a recently proposed entity authentication protocol in which a physical unclonable key is interrogated by random coherent states of light, and the quadratures of the scattered light are analyzed by means of a coarse-grained homodyne detection. We derive a sufficient condition for the prot...

[Phys. Rev. A 97, 012324] Published Mon Jan 22, 2018

]]>Quantum entanglement is an indispensable resource for many significant quantum information processing tasks. However, in practice, it is difficult to distribute quantum entanglement over a long distance, due to the absorption and noise in quantum channels. A solution to this challenge is a quantum r...

[Phys. Rev. A 97, 012325] Published Mon Jan 22, 2018

]]>Accurate intercombination transition rates ($A$), arising from the $2{s}^{2}2pnl$ ($n$ = 3, 4, 5; $l$ = $s,p,d$) and $2s2{p}^{3}$ configurations of ${\mathrm{N}}^{+}$, are reported. Wavefunctions for the studied states in ${\mathrm{N}}^{+}$ are determined using the multiconfiguration Dirac-Hartree-Fock (MCDHF) method and account for the effects of vale...

[Phys. Rev. A 97, 012510] Published Mon Jan 22, 2018

]]>It is shown that triple ionization (TI) of the ${\mathrm{Se}}^{2+}$ ion is mainly formed in two ways: (i) Auger cascade following single ionization of the $3p$ shell and (ii) direct double ionization (DDI) with subsequent autoionization. A good agreement with recent experimental measurements is obtained when one of e...

[Phys. Rev. A 97, 012705] Published Mon Jan 22, 2018

]]>Positronium (Ps) scattering by noble-gas atoms (He, Ne, Ar, Kr, and Xe) is studied in the frozen-target approximation and with inclusion of the van der Waals interaction. Single-particle electron and positron states in the field of the target atom are calculated, with the system enclosed by a hard s...

[Phys. Rev. A 97, 012706] Published Mon Jan 22, 2018

]]>Solving the time-dependent Schrödinger equation numerically within the framework of an *ab initio* model, the breakdown of the dipole approximation in modeling the ionization and excitation dynamics of a hydrogen atom exposed to an intense 1.36-keV x-ray laser pulse is investigated in some detail. The...

[Phys. Rev. A 97, 013415] Published Mon Jan 22, 2018

]]>We present low-frequency approximation (LFA) for high-order harmonic generation (HHG) process. LFA represents the lowest-order term of an expansion of the final-state interaction matrix element in powers of the laser-field frequency $\omega $. In this approximation the plane-wave recombination matrix elemen...

[Phys. Rev. A 97, 013416] Published Mon Jan 22, 2018

]]>Wavelength scaling of high-order harmonic generation (HHG) in a non-Born-Oppenheimer treatment of ${\mathrm{H}}_{2}{}^{+}$ is investigated by numerical simulations of the time-dependent Schrödinger equation. The results show that the decrease in the wavelength-dependent HHG yield is reduced compared to that in the fixed...

[Phys. Rev. A 97, 013417] Published Mon Jan 22, 2018

]]>A quantum system exhibiting $\mathcal{PT}$ symmetry is a Bose-Einstein condensate in a double-well potential with balanced particle gain and loss, which is described in the mean-field limit by a Gross-Pitaevskii equation with a complex potential. A possible experimental realization of such a system by embedding...

[Phys. Rev. A 97, 013623] Published Mon Jan 22, 2018

]]>We consider bosonic atoms loaded into optical lattices with cavity-mediated infinite-range interactions. Competing short- and global-range interactions cultivate a rich phase diagram. With a systematic field-theoretical perspective, we present an *analytical* construction of a global ground-state phas...

[Phys. Rev. A 97, 013624] Published Mon Jan 22, 2018

]]>We consider the fate of Bose-Einstein condensation with time-reversal symmetry and inversion symmetry in a spin-orbit-coupled bilayer system. When these two symmetry operators commute, all the single-particle bands are exactly twofold degenerate in the momentum space. The scattering in the twofold-d...

[Phys. Rev. A 97, 013625] Published Mon Jan 22, 2018

]]>We study the classical correlation function of spatially incoherent beams with a phase aberration in the beam path. On the basis of our experimental measurements and in the optical coherence theory, we show that the effects of phase disturbances, independently of their kind and without need of coord...

[Phys. Rev. A 97, 013832] Published Mon Jan 22, 2018

]]>Single atoms form a model system for understanding the limits of single-photon detection. Here, we develop a non-Markovian theory of single-photon absorption by a two-level atom to place limits on the absorption (transduction) time. We show the existence of a finite rise time in the probability of e...

[Phys. Rev. A 97, 013833] Published Mon Jan 22, 2018

]]>We propose to couple the optical orientational nonlinearities of liquid crystals with their ability to self-organize to tailor them to control space-variant-polarized optical fields in a nonlinear manner. Experimental demonstration is made using a liquid crystal light valve that behaves like a light...

[Phys. Rev. A 97, 013834] Published Mon Jan 22, 2018

]]>The most typical ingredient of topologically protected quantum states is magnetic fluxes. In a system of spins, complex-valued interaction parameters give rise to a flux, if their phases do not add up to zero along a closed loop. Here we apply periodic driving, a powerful tool for quantum engineerin...

[Phys. Rev. A 97, 010302(R)] Published Fri Jan 19, 2018

]]>We report an experimental observation of the interatomic Coulombic decay (ICD) and radiative charge-transfer (RCT) processes in a Ne dimer $\left(e,2e\right)$ following a 380-eV electron impact. By detecting the $\mathrm{N}{\mathrm{e}}^{+}-\mathrm{N}{\mathrm{e}}^{+}$ cation pair and one of the emitted electrons in coincidence, the fingerprint of the ICD proce...

[Phys. Rev. A 97, 010701(R)] Published Fri Jan 19, 2018

]]>Using a superconducting circuit QED device, we present a theoretical study of real-time quantum state estimation via the quantum Bayesian approach. Suitable conditions under which the quantum Bayesian approach can accurately update the density matrix of the qubit are analyzed. We also consider the c...

[Phys. Rev. A 97, 012119] Published Fri Jan 19, 2018

]]>We address parameter estimation in two-level systems exhibiting level anticrossing and prove that universally optimal strategies for parameter estimation may be designed. In fact, we find a parameter-independent measurement scheme, leading to the ultimate quantum precision, independently of the valu...

[Phys. Rev. A 97, 012120] Published Fri Jan 19, 2018

]]>We investigate a parity-time ($\mathcal{PT}$)-symmetric system that consists of two symmetrically coupled asymmetric dimers. The enclosed magnetic flux controls the $\mathcal{PT}$ phase transition. The system can reenter the exact $\mathcal{PT}$-symmetric phase from a broken $\mathcal{PT}$-symmetric phase with large non-Hermiticity. Two-state coa...

[Phys. Rev. A 97, 012121] Published Fri Jan 19, 2018

]]>Entanglement degradation of orbital-angular-momentum modes can be prevented using adaptive optics. The results prove the possibility of significantly reducing the crosstalk of modes, thereby making entanglement available even under moderate atmospheric turbulence conditions.

[Phys. Rev. A 97, 012321] Published Fri Jan 19, 2018

]]>We study the problem of optimal preparation of a bipartite entangled state, which remains entangled the longest time under action of local qubit noises. We show that for unital noises, such a state is always maximally entangled, whereas for nonunital noises, it is not. We develop a decomposition tec...

[Phys. Rev. A 97, 012322] Published Fri Jan 19, 2018

]]>Hypergraph states, a generalization of graph states, constitute a large class of quantum states with intriguing nonlocal properties, and they have promising applications in quantum information science and technology. In this paper, we study some features of an independently proposed generalization o...

[Phys. Rev. A 97, 012323] Published Fri Jan 19, 2018

]]>We report on the determination of the dynamical polarizability of ultracold erbium atoms in the ground and in one excited state at three different wavelengths, which are particularly relevant for optical trapping. Our study combines experimental measurements of the light shift and theoretical calcul...

[Phys. Rev. A 97, 012509] Published Fri Jan 19, 2018

]]>Dark solitons are traditionally considered to exist in defocusing Kerr nonlinearity media. We investigate dark quadratic solitons with a focusing effective Kerr nonlinearity and a sine-oscillatory nonlocal response. A nonlinear refractive index with a focusing sine-oscillatory response leads to a de...

[Phys. Rev. A 97, 013829] Published Fri Jan 19, 2018

]]>We propose a method to manipulate four-level systems with specific coupling configurations by means of time-dependent couplings and constant energy shifts (detunings in quantum-optical realizations). We inversely engineer the Hamiltonian, in ladder, tripod, or diamond configurations, to prepare arbi...

[Phys. Rev. A 97, 013830] Published Fri Jan 19, 2018

]]>Edge states of photonic crystals have attracted much attention for the potential applications, such as high transmission waveguide bends, spin-dependent splitters, and one-way photonic circuits. Here, we theoretically discuss and experimentally observe the deterministic edge states in checkerboard p...

[Phys. Rev. A 97, 013831] Published Fri Jan 19, 2018

]]>Electron correlation plays a crucial role in quantum many-body physics ranging from molecular bonding and strong-field–induced multielectron ionization, to superconducting in materials. Understanding the dynamic electron correlation in the photoionization of relatively simple quantum three-body syst...

[Phys. Rev. A 97, 013414] Published Thu Jan 18, 2018

]]>We propose a concept of disordered resonant media, which are characterized by random variations of their parameters along the light propagation direction. In particular, a simple model of disorder considered in the paper implies random change of the density of active particles (two-level atoms). Wit...

[Phys. Rev. A 97, 013826] Published Thu Jan 18, 2018

]]>We describe and demonstrate a method to control a detuned movable-mirror Fabry-Pérot cavity using radiation pressure in the presence of a strong optical spring. At frequencies below the optical spring resonance, self-locking of the cavity is achieved intrinsically by the optomechanical (OM) interact...

[Phys. Rev. A 97, 013827] Published Thu Jan 18, 2018

]]>We theoretically investigate the generation of heralded entanglement between two identical atoms via cavity-assisted photon scattering in two different configurations, namely, either both atoms confined in the same cavity or trapped into locally separated ones. Our protocols are given by a very simp...

[Phys. Rev. A 97, 013828] Published Thu Jan 18, 2018

]]>We study the dynamics of discrete-time quantum walk using quantum coin operations, $\widehat{C}\left({\theta}_{1}\right)$ and $\widehat{C}\left({\theta}_{2}\right)$, in time-dependent periodic sequence. For the two-period quantum walk with the parameters ${\theta}_{1}$ and ${\theta}_{2}$ in the coin operations we show that the standard deviation $\left[{\sigma}_{{\theta}_{1},{\theta}_{2}}\left(t\right)\right]$ is the same as the minimum o...

[Phys. Rev. A 97, 012116] Published Wed Jan 17, 2018

]]>We consider the temporal correlations of the quantum state of a qubit subject to simultaneous continuous measurement of two noncommuting qubit observables. Such qubit state correlators are defined for an ensemble of qubit trajectories, which has the same fixed initial state and can also be optionall...

[Phys. Rev. A 97, 012118] Published Wed Jan 17, 2018

]]>Using the semiclassical two-step model for strong-field ionization we investigate the interference structures emerging in strong-field photoelectron holography, taking into account the Coulomb potential of the atomic core. For every kind of the interference pattern predicted by the three-step model,...

[Phys. Rev. A 97, 013411] Published Wed Jan 17, 2018

]]>We propose a theoretical scheme for atomic cooling, i.e., the compression of both velocity and position distribution of particles in motion. This is achieved by collisions of the particles with a combination of a moving atomic mirror and a moving atom diode. An atom diode is a unidirectional barrier...

[Phys. Rev. A 97, 013412] Published Wed Jan 17, 2018

]]>Transient near fields around metallic nanotips drive many applications, including the generation of ultrafast electron pulses and their use in electron microscopy. We have investigated the electron emission from a gold nanotip driven by midinfrared few-cycle laser pulses. We identify a low-energy pe...

[Phys. Rev. A 97, 013413] Published Wed Jan 17, 2018

]]>We present a numerical study of the Higgs mode in an ultracold confined Fermi gas after an interaction quench and find a dynamical vanishing of the superfluid order parameter. Our calculations are done within a microscopic density-matrix approach in the Bogoliubov–de Gennes framework which takes the...

[Phys. Rev. A 97, 013619] Published Wed Jan 17, 2018

]]>We propose and demonstrate a method for calibrating atomic trajectories in a large-area dual-atom-interferometer gyroscope. The atom trajectories are monitored by modulating and delaying the Raman transition, and they are precisely calibrated by controlling the laser orientation and the bias magneti...

[Phys. Rev. A 97, 013620] Published Wed Jan 17, 2018

]]>One-dimensional spinless Bose and Fermi gases with contact interactions have the close interrelation via Girardeau's Bose-Fermi mapping, leading to the correspondences in their energy spectra and thermodynamics. However, correlation functions are in general not identical between these systems. We de...

[Phys. Rev. A 97, 013621] Published Wed Jan 17, 2018

]]>Prethermalization refers to the relaxation to a quasistationary state before reaching thermal equilibrium. Recently, it was found that not only local conserved quantities but also entanglement plays a key role in a special type of prethermalization, which we refer to as entanglement prethermalizatio...

[Phys. Rev. A 97, 013622] Published Wed Jan 17, 2018

]]>Propagation of coherent light in a Kerr nonlinear medium can be mapped onto a flow of an equivalent fluid. Here we use this mapping to model the conditions in the vicinity of a rotating black hole as a Laguerre–Gauss vortex beam. We describe weak fluctuations of the phase and amplitude of the electr...

[Phys. Rev. A 97, 013823] Published Wed Jan 17, 2018

]]>Surveys on wave propagation in dispersive media have been limited since the pioneering work of Sommerfeld [Ann. Phys. **349**, 177 (1914)] by the presence of branches in the integral expression of the wave function. In this article a method is proposed to eliminate these critical branches and hence to e...

[Phys. Rev. A 97, 013824] Published Wed Jan 17, 2018

]]>We demonstrate that the open quantum Rabi model (QRM) exhibits a second-order dissipative phase transition (DPT) and propose a method to observe this transition with trapped ions. The interplay between the ultrastrong qubit-oscillator coupling and the oscillator damping brings the system into a stea...

[Phys. Rev. A 97, 013825] Published Wed Jan 17, 2018

]]>[Phys. Rev. A 97, 019903] Published Wed Jan 17, 2018

]]>High-order-harmonic generation by a highly nonlinear interaction of infrared laser fields with matter allows for the generation of attosecond pulses in the XUV spectral regime. This process, well established for atoms, has been recently extended to the condensed phase. Remarkably well-pronounced har...

[Phys. Rev. A 97, 011401(R)] Published Tue Jan 16, 2018

]]>We point out that the momentum distribution is not a proper observable for a system of anyons in two dimensions. In view of anyons as Wilczek's composite charged flux tubes, this is a consequence of the fact that the orthogonal components of the kinetic momentum operator do not commute at the positi...

[Phys. Rev. A 97, 011601(R)] Published Tue Jan 16, 2018

]]>We introduce an enlarged state, which combines both pre- and postselection states at a given time $t$ in between the pre- and postselection. Based on this form, quantum weak and modular values can be completely interpreted as expectation values of a linear combination of given operators in the enlarge...

[Phys. Rev. A 97, 012112] Published Tue Jan 16, 2018

]]>A method for calculating the electronic levels in the compact superheavy nuclear quasimolecules, based on solving the two-center Dirac equation using the multipole expansion of two-center potential, is developed. For the internuclear distances up to $d\sim 100$ fm, such technique reveals a quite fast conv...

[Phys. Rev. A 97, 012113] Published Tue Jan 16, 2018

]]>We study the entropy dynamics of a dephasing model, where a two-level system (TLS) is coupled with a squeezed thermal bath via a nondemolition interaction. This model is exactly solvable, and the time-dependent states of both the TLS and its bath can be obtained exactly. Based on these states, we ca...

[Phys. Rev. A 97, 012114] Published Tue Jan 16, 2018

]]>We study the dynamics of the Lipkin-Meshkov-Glick (LMG) model with a finite number of spins. In the thermodynamic limit, the ground state of the LMG model with an isotropic Hamiltonian in the broken phase breaks to a mean-field ground state with a certain direction. However, when the spin number $N$ i...

[Phys. Rev. A 97, 012115] Published Tue Jan 16, 2018

]]>Quantum key distribution (QKD) offers a way for establishing information-theoretical secure communications. An important part of QKD technology is a high-quality random number generator for the quantum-state preparation and for post-processing procedures. In this work, we consider a class of prepare...

[Phys. Rev. A 97, 012311] Published Tue Jan 16, 2018

]]>An ensemble of nitrogen-vacancy (NV) centers coupled to a circuit QED device is shown to enable an efficient, high-fidelity generation of high-N00N states. Instead of first creating entanglement and then increasing the number of entangled particles $N$, our source of high-N00N states first prepares a ...

[Phys. Rev. A 97, 012312] Published Tue Jan 16, 2018

]]>Measurement-device-independent quantum key distribution (MDI-QKD) protocol was proposed to remove all the detector side channel attacks, while its security relies on the trusted encoding systems. Here we propose a one-sided MDI-QKD (1SMDI-QKD) protocol, which enjoys detection loophole-free advantage...

[Phys. Rev. A 97, 012313] Published Tue Jan 16, 2018

]]>We prove that as conjectured by Acín *et al.* [Phys. Rev. A **93**, 040102(R) (2016)], two bits of randomness can be certified in a device-independent way from one bit of entanglement using the maximal quantum violation of Gisin's elegant Bell inequality. This suggests a surprising connection between maxi...

[Phys. Rev. A 97, 012314] Published Tue Jan 16, 2018

]]>Encoding schemes and error-correcting codes are widely used in information technology to improve the reliability of data transmission over real-world communication channels. Quantum information protocols can further enhance the performance in data transmission by encoding a message in quantum states...

[Phys. Rev. A 97, 012315] Published Tue Jan 16, 2018

]]>There exist zero-temperature states in quantum many-body systems that are fully factorized, thereby possessing vanishing entanglement, and hence being of no use as resource in quantum information processing tasks. Such states can become useful for quantum protocols when the temperature of the system...

[Phys. Rev. A 97, 012316] Published Tue Jan 16, 2018

]]>In the Gaussian-modulated coherent-states (GMCS) quantum key distribution (QKD) protocol, Alice prepares quantum states *actively*: For each transmission, Alice generates a pair of Gaussian-distributed random numbers, encodes them on a weak coherent pulse using optical amplitude and phase modulators, ...

[Phys. Rev. A 97, 012317] Published Tue Jan 16, 2018

]]>The performance of quantum-error-correction schemes depends sensitively on the physical realizations of the qubits and the implementations of various operations. For example, in quantum-dot spin qubits, readout is typically much slower than gate operations, and conventional surface-code implementati...

[Phys. Rev. A 97, 012318] Published Tue Jan 16, 2018

]]>Single-particle and coincidence distributions of photons are analyzed for the noncollinear frequency-degenerate type-I regime of spontaneous parametric down-conversion. Noncollinearity itself is shown to provide a new mechanism of strong broadening of the single-particle distributions in Cartesian c...

[Phys. Rev. A 97, 012319] Published Tue Jan 16, 2018

]]>Here, we numerically simulate probabilistic elementary entangling operations between rail-encoded photons for the purpose of scalable universal quantum computation or communication. We propose grouping logical qubits into single-photon blocks wherein single-qubit rotations and the controlled-not (cn...

[Phys. Rev. A 97, 012320] Published Tue Jan 16, 2018

]]>We report high-resolution Doppler-free two-photon excitation spectroscopy of Xe from the ground state to the $5{p}^{5}\left({}^{2}P_{3/2}\right)6p\phantom{\rule{0.16em}{0ex}}\phantom{\rule{0.16em}{0ex}}{}^{2}[3/2]_{2}$ electronic excited state. This is a first step to developing a comagnetometer using polarized ${}^{129}\mathrm{Xe}$ atoms for planned neutron electric dipole moment measurements at TRIUMF...

[Phys. Rev. A 97, 012507] Published Tue Jan 16, 2018

]]>The lithium atom in its ground state can bind positronium (Ps) forming LiPs, an electronically stable system. In this study we use the fixed node diffusion Monte Carlo method to perform a detailed investigation of the internal structure of LiPs, establishing to what extent it could be described by s...

[Phys. Rev. A 97, 012508] Published Tue Jan 16, 2018

]]>We present a theoretical model to investigate double-core-hole-state formation in molecules through sequential absorption of two x-ray photons from a femtosecond laser pulse. A complete time-dependent quantum description taking into account x-ray absorption and nuclear dynamics explicitly and Auger ...

[Phys. Rev. A 97, 013406] Published Tue Jan 16, 2018

]]>Decoherence of quantum systems due to uncontrolled fluctuations of the environment presents fundamental obstacles in quantum science. Clock transitions which are insensitive to such fluctuations are used to improve coherence, however, they are not present in all systems or for arbitrary system param...

[Phys. Rev. A 97, 013407] Published Tue Jan 16, 2018

]]>We continuously observe dynamical decoupling in a spin-1 quantum gas using a weak optical measurement of spin precession. Continuous dynamical decoupling modifies the character and energy spectrum of spin states to render them insensitive to parasitic fluctuations. Continuous observation measures th...

[Phys. Rev. A 97, 013408] Published Tue Jan 16, 2018

]]>Absolute cross-section measurements for photoionization of C${}^{+}$ near the $K$ edge are reported with high energy resolution. The transition parameters derived for the 1$s$-2$p$ excitations may open a window into the important field of many-electron processes in atomic systems.

[Phys. Rev. A 97, 013409] Published Tue Jan 16, 2018

]]>It is a common view that rotational motion in a superfluid can exist only in the presence of topological defects, i.e., quantized vortices. However, in our numerical studies on the merging of two concentric Bose-Einstein condensates with axial symmetry in two-dimensional space, we observe the emerge...

[Phys. Rev. A 97, 013612] Published Tue Jan 16, 2018

]]>The expansion dynamics of an initially confined wave packet is numerically studied in the presence of a disordered potential and a uniform bias force. Stationary profiles of the wave packet are found for a white-noise disorder when the ratio of the force and the disorder is below a critical value, whereas delocalization is found to always occur when the disorder is correlated.

[Phys. Rev. A 97, 013613] Published Tue Jan 16, 2018

]]>We study the formation of stable bright solitons in quasi-one-dimensional (quasi-1D) spin-orbit- (SO-) and Rabi-coupled two pseudospinor dipolar Bose-Einstein condensates (BECs) of ${}^{164}\mathrm{Dy}$ atoms in the presence of repulsive contact interactions. As a result of the combined attraction-repulsion effect ...

[Phys. Rev. A 97, 013614] Published Tue Jan 16, 2018

]]>Ultracold gases offer an unprecedented opportunity to engineer disorder and interactions in a controlled manner. In an effort to understand the interplay between disorder, dipolar interactions, and quantum degeneracy, we study two-dimensional hard-core dipolar lattice bosons in the presence of on-si...

[Phys. Rev. A 97, 013615] Published Tue Jan 16, 2018

]]>We present the first experimental demonstration of a multiple radio-frequency dressed potential for the configurable magnetic confinement of ultracold atoms. We load cold ${}^{87}\mathrm{Rb}$ atoms into a double-well potential with an adjustable barrier height, formed by three radio-frequencies applied to atoms in ...

[Phys. Rev. A 97, 013616] Published Tue Jan 16, 2018

]]>The domain-area distribution in the phase transition dynamics of ${Z}_{2}$ symmetry breaking is studied theoretically and numerically for segregating binary Bose-Einstein condensates in quasi-two-dimensional systems. Due to the dynamic-scaling law of the phase ordering kinetics, the domain-area distributio...

[Phys. Rev. A 97, 013617] Published Tue Jan 16, 2018

]]>Assuming that two-component Fermi gases with opposite artificial magnetic fields on a square optical lattice are well described by the so-called time-reversal-symmetric Hofstadter-Hubbard model, we explore the thermal superfluid properties along with the critical Berezinskii-Kosterlitz-Thouless (BKT...

[Phys. Rev. A 97, 013618] Published Tue Jan 16, 2018

]]>We study theoretically the interaction of temporal localized states in all fiber cavities and microresonator-based optical frequency comb generators. We show that Cherenkov radiation emitted in the presence of third-order dispersion breaks the symmetry of the localized structures interaction and gre...

[Phys. Rev. A 97, 013816] Published Tue Jan 16, 2018

]]>We illuminate an analytical model of soliton interactions in lead glass by analogizing to a gravitational force system. The orbits of spiraling solitons under a long-range interaction are given explicitly and demonstrated to follow Newton's second law of motion and the Binet equation by numerical si...

[Phys. Rev. A 97, 013817] Published Tue Jan 16, 2018

]]>Topological and strongly correlated materials are exciting frontiers in condensed-matter physics, married prominently in studies of the fractional quantum Hall effect [H. L. Stormer *et al.*, Rev. Mod. Phys. **71**, S298 (1999)], There is an active effort to develop synthetic materials where the microsco...

[Phys. Rev. A 97, 013818] Published Tue Jan 16, 2018

]]>We give a derivation for the indirect interaction between two magnetic dipoles induced by the quantized electromagnetic field. It turns out that the interaction between permanent dipoles directly returns to the classical form; the interaction between transition dipoles does not directly return to th...

[Phys. Rev. A 97, 013819] Published Tue Jan 16, 2018

]]>We propose a scheme to generate macroscopic superposition states (MSSs) in spin ensembles, where a coherent driving field is applied to accelerate the generation of macroscopic superposition states. The numerical calculation demonstrates that this approach allows us to generate a superposition of tw...

[Phys. Rev. A 97, 013820] Published Tue Jan 16, 2018

]]>We investigate the electric quadrupole interaction of an alkali-metal atom with guided light in the fundamental and higher-order modes of a vacuum-clad ultrathin optical fiber. We calculate the quadrupole Rabi frequency, the quadrupole oscillator strength, and their enhancement factors. In the examp...

[Phys. Rev. A 97, 013821] Published Tue Jan 16, 2018

]]>We reveal a behavior of screwdriving of a surface plasmonic field formed near a surface of strongly chiral material, where lateral force and torque can be provided by the quantum spin Hall effect of light simultaneously. We study the role of chirality strength of the material in optical manipulating...

[Phys. Rev. A 97, 013822] Published Tue Jan 16, 2018

]]>We present measurements of the hyperfine splitting in the ${}^{173}\mathrm{Yb}6s6p\phantom{\rule{0.16em}{0ex}}{}^{1}P_{{}_{1}^{\mathrm{o}}}({F}^{\prime}=3/2,7/2)$ states that disagree significantly with those measured previously by Das and Natarajan [Phys. Rev. A **76**, 062505 (2007)]. We point out inconsistencies in their measurements and suggest that their error is due to opti...

[Phys. Rev. A 97, 016501] Published Tue Jan 16, 2018

]]>Hyperentanglement—simultaneous entanglement between multiple degrees of freedom of two or more systems—has been used to enhance quantum information tasks such as quantum communication and photonic quantum computing. Here we show that hyperentanglement can lead to increased quantum advantage in metro...

[Phys. Rev. A 97, 010301(R)] Published Fri Jan 12, 2018

]]>Quantum mechanics in noncommutative space modifies the standard result of the Aharonov-Bohm effect for electrons and other recent quantum effects. Here we obtain the phase in noncommutative space for the Spavieri effect, a generalization of Aharonov-Bohm effect which involves a coherent superpositio...

[Phys. Rev. A 97, 012109] Published Fri Jan 12, 2018

]]>Broadly understood decoherence processes in quantum electrodynamics, induced by neglecting either the radiation [L. Landau, Z. Phys. **45**, 430 (1927)] or the charged matter [N. Bohr and L. Rosenfeld, K. Danske Vidensk. Selsk, Math.-Fys. Medd. **XII**, 8 (1933)], have been studied from the dawn of the theo...

[Phys. Rev. A 97, 012110] Published Fri Jan 12, 2018

]]>The uncertainty relation for continuous variables due to Byałinicki-Birula and Mycielski [I. Białynicki-Birula and J. Mycielski, Commun. Math. Phys. **44**, 129 (1975)] expresses the complementarity between two $n$-tuples of canonically conjugate variables $({x}_{1},{x}_{2},...,{x}_{n})$ and $({p}_{1},{p}_{2},...,{p}_{n})$ in terms of Sha...

[Phys. Rev. A 97, 012111] Published Fri Jan 12, 2018

]]>We analyze the potential for different types of searches using the formalism of scattering random walks on quantum computers. Given a particular type of graph consisting of nodes and connections, a “tree maze,” we would like to find a selected final node as quickly as possible, faster than any class...

[Phys. Rev. A 97, 012308] Published Fri Jan 12, 2018

]]>We introduce a framework to analyze quantum algorithms with the renormalization group (RG). To this end, we present a detailed analysis of the real-space RG for discrete-time quantum walks on fractal networks and show how deep insights into the analytic structure as well as generic results about the...

[Phys. Rev. A 97, 012309] Published Fri Jan 12, 2018

]]>We propose a pilot-multiplexed continuous-variable quantum key distribution (CVQKD) scheme based on a local local oscillator (LLO). Our scheme utilizes time-multiplexing and polarization-multiplexing techniques to dramatically isolate the quantum signal from the pilot, employs two heterodyne detecto...

[Phys. Rev. A 97, 012310] Published Fri Jan 12, 2018

]]>A density-functional theory is developed based on the Maxwell-Schrödinger equation with an internal magnetic field in addition to the external electromagnetic potentials. The basic variables of this theory are the electron density and the total magnetic field, which can equivalently be represented a...

[Phys. Rev. A 97, 012504] Published Fri Jan 12, 2018

]]>The $1snp\phantom{\rule{0.16em}{0ex}}{}^{3}P_{J}$ fine structure of high Rydberg states in helium has been measured by microwave spectroscopy of single-photon transitions from $1sns\phantom{\rule{0.16em}{0ex}}{}^{3}S_{1}$ levels in pulsed supersonic beams. For states with principal quantum numbers in the range from $n=34$ to 36, the $J=0\to 2$ and $J=1\to 2$ fine structure intervals we...

[Phys. Rev. A 97, 012505] Published Fri Jan 12, 2018

]]>Relativistic atomic structure calculations are carried out in alkaline-earth-metal ions using a semiempirical-core-potential approach. The systems are partitioned into frozen-core electrons and an active valence electron. The core orbitals are defined by a Dirac-Hartree-Fock calculation using the gr...

[Phys. Rev. A 97, 012506] Published Fri Jan 12, 2018

]]>We reported elastic (integrated and differential), momentum-transfer, and excitation cross sections for electron collisions with methylene radical. $R$-matrix method is employed to calculate the cross section for electron energies ranging from 0.01 to 15 eV. The results of 1-state, 3-state, 15-state, ...

[Phys. Rev. A 97, 012703] Published Fri Jan 12, 2018

]]>We present an effective two-channel model for reactive collisions of cold atoms. It augments elastic molecular channels with an irreversible, inelastic loss channel. Scattering is studied with the distorted-wave Born approximation and yields general expressions for angular momentum resolved cross se...

[Phys. Rev. A 97, 012704] Published Fri Jan 12, 2018

]]>Ultracold fermionic ${}^{23}$Na${}^{40}$K polar molecules are produced in their ground rovibrational state. A multilevel stimulated Raman adiabatic passage (STIRAP) state-transfer process is employed with an intermediate state having an unresolved hyperfine structure, which can be a situation commonly encountered in performing the state transfer.

[Phys. Rev. A 97, 013405] Published Fri Jan 12, 2018

]]>When describing the low-energy physics of bosons in a double-well potential with a high barrier between the wells and sufficiently weak atom-atom interactions, one can, to a good approximation, ignore the high-energy states and thereby obtain an effective two-mode model. Here we show that the regime...

[Phys. Rev. A 97, 013609] Published Fri Jan 12, 2018

]]>We address the discrimination between attractive and repulsive interaction in systems made of two identical bosons propagating on a one-dimensional lattice, and suggest a probing scheme exploiting the dynamical properties of the corresponding two-particle quantum walks. In particular, we show that t...

[Phys. Rev. A 97, 013610] Published Fri Jan 12, 2018

]]>A general challenge in various quantum experiments and applications is to develop suitable sources for coherent particles. In particular, recent progress in microscopy, interferometry, metrology, decoherence measurements, and chip-based applications rely on intensive, tunable, coherent sources for f...

[Phys. Rev. A 97, 013611] Published Fri Jan 12, 2018

]]>We present the results of an experimental and numerical investigation into temporally nonlocal coherent interactions between ultrashort pulses, mediated by Raman coherence, in a gas-filled kagome-style hollow-core photonic-crystal fiber. A pump pulse first sets up the Raman coherence, creating a ref...

[Phys. Rev. A 97, 013814] Published Fri Jan 12, 2018

]]>The Bloch equation and its variants constitute the fundamental dynamical model for arbitrary two-level systems. Many important processes, including those in more complicated systems, can be modeled and understood through the two-level approximation. It is therefore of widespread relevance, especiall...

[Phys. Rev. A 97, 013815] Published Fri Jan 12, 2018

]]>We describe a direct method to experimentally determine local two-qubit invariants by performing interferometric measurements on multiple copies of a given two-qubit state. We use this framework to analyze two different kinds of two-qubit invariants of Makhlin and Jing *et al.* These invariants allow ...

[Phys. Rev. A 97, 012107] Published Thu Jan 11, 2018

]]>We demonstrate an original development of path-integral quantization in the case of a multiply connected configuration space of indistinguishable charged particles on a 2D manifold and exposed to a strong perpendicular magnetic field. The system occurs to be exceptionally homotopy-rich and the struc...

[Phys. Rev. A 97, 012108] Published Thu Jan 11, 2018

]]>