The problem of gaining information about a qubit’s environment by a sequence of single-shot projective measurements applied to the qubit is analyzed in detail. The theory is applied to the case of NV centers, and it is found that recent results from the literature can be explained by classical concepts.

[Phys. Rev. A 99, 062113] Published Thu Jun 20, 2019

]]>Manipulation of qudits in optical tables is a difficult and nonscalable task. The use of integrated optical circuits opens new possibilities for the generation, manipulation, and characterization of high dimensional states besides the ease of transmission of these states through an optical fiber. In...

[Phys. Rev. A 99, 062324] Published Thu Jun 20, 2019

]]>Quantum coherence was recently formalized as a physical resource to measure the strength of superposition. Based on the resource theory, we present a systematic framework that connects a coherence measure to the security of quantum key distribution. By considering a generic entanglement-based key di...

[Phys. Rev. A 99, 062325] Published Thu Jun 20, 2019

]]>Phase-randomized optical homodyne detection is a well-known technique for performing quantum state tomography. So far, it has been mainly considered a sophisticated tool for laboratory experiments but unsuitable for practical applications. In this work, we change the perspective and employ this tech...

[Phys. Rev. A 99, 062326] Published Thu Jun 20, 2019

]]>We report an angle-resolved electron-energy-loss spectroscopy study on the valence excitations of $\mathrm{S}{\mathrm{F}}_{6}$. Momentum-transfer-dependent generalized oscillator strengths (GOSs) or GOS profiles of the low-lying valence excitations have been derived from electron-energy-loss spectra measured at an incident ...

[Phys. Rev. A 99, 062708] Published Thu Jun 20, 2019

]]>We theoretically study high-harmonic generation (HHG) from transition-metal elements Mn and ${\mathrm{Mn}}^{+}$ using full-dimensional, all-electron, first-principles simulations. The HHG spectra calculated with the time-dependent complete-active-space self-consistent-field (TD-CASSCF) and occupation-restricted mul...

[Phys. Rev. A 99, 063420] Published Thu Jun 20, 2019

]]>We improve the efficiency of sawtooth-wave adiabatic-passage cooling for strontium atoms in three dimensions and combine it with standard narrow-line laser cooling. With this technique, we create strontium magneto-optical traps with $6\times {10}^{7}$ bosonic ${}^{88}\mathrm{Sr}$ ($1\times {10}^{7}$ fermionic ${}^{87}\mathrm{Sr}$) atoms at phase-space dens...

[Phys. Rev. A 99, 063421] Published Thu Jun 20, 2019

]]>Recent experimental and theoretical results show that weakly interacting atomic Bose-Bose mixtures with attractive interspecies interaction are stabilized by beyond-mean-field effects. Here we consider the peculiar properties of these systems in a strictly one-dimensional configuration, taking also ...

[Phys. Rev. A 99, 063618] Published Thu Jun 20, 2019

]]>We study a system of penetrable bosons embedded in a spherical surface. Under the assumption of weak interaction between the particles, the ground state of the system is, to a good approximation, a pure condensate. We employ thermodynamic arguments to investigate, within a variational ansatz for the...

[Phys. Rev. A 99, 063619] Published Thu Jun 20, 2019

]]>The time evolution of spin-energy correlations in a very weakly interacting Fermi gas of ${}^{6}$Li produces complex spin-density profiles, which are observed and quantitatively explained by a one-dimensional mean-field model. This system exhibits rich collective dynamics for exploring the interplay between spin, motion, Fermi statistics, and interactions in many-body systems.

[Phys. Rev. A 99, 063620] Published Thu Jun 20, 2019

]]>In recent years, guided acoustic wave Brillouin scattering has become an important tool in photonics, serving as the basis for everything from new forms of information processing to silicon lasers. Due to low losses and long interaction lengths, fiber optic systems offer an intriguing platform to ha...

[Phys. Rev. A 99, 063826] Published Thu Jun 20, 2019

]]>Superposition of multiple indistinguishable two-photon paths is introduced by means of a digital wave front encoding technique to design a spatially phase-correlated wave front of a light field, which could result in a superbunching effect with a bunching peak much larger than 2, the theoretical bun...

[Phys. Rev. A 99, 063827] Published Thu Jun 20, 2019

]]>We investigate the driven quantum phase transition between the oscillating motion and the classical nearly free rotations of the Josephson pendulum coupled to a harmonic oscillator in the presence of dissipation. We refer to this as the Josephson-Rabi model. This model describes the standard setup o...

[Phys. Rev. A 99, 063828] Published Thu Jun 20, 2019

]]>We address a fundamental question of quantum optics: Can a beam of light mediate coherent Hamiltonian interactions between two distant quantum systems? This is an intriguing question whose answer is not *a priori* clear, since the light carries away information about the systems and might be subject t...

[Phys. Rev. A 99, 063829] Published Thu Jun 20, 2019

]]>We couple the full three-dimensional *ab initio* quantum evolution of the light pulse polarization in interaction with an atom with a propagation model to simulate the propagation of ultrashort laser pulses over macroscopic dimensions, in the presence of self-generated harmonics up to order 11. We evi...

[Phys. Rev. A 99, 061401(R)] Published Wed Jun 19, 2019

]]>We investigate a uniformly coupled non-Hermitian system with asymmetric coupling amplitude. The asymmetric coupling equals to a symmetric coupling threaded by an imaginary gauge field. In a closed configuration, the imaginary gauge field leads to an imaginary magnetic flux, which induces a non-Hermi...

[Phys. Rev. A 99, 062112] Published Wed Jun 19, 2019

]]>In this paper, we extend the results of an earlier paper [G. Mouloudakis and P. Lambropoulos, Phys. Rev. A **97**, 053413 (2018)] in which we had demonstrated the limitations of the notion of nonresonant multiphoton ionization, in the exploration of photon statistics effects in nonlinear processes. Thro...

[Phys. Rev. A 99, 063419] Published Wed Jun 19, 2019

]]>We study interacting ultracold atoms in a three-dimensional (3D) harmonic trap with spin-selective dissipations, which can be effectively described by non-Hermitian parity-time ($\mathcal{PT}$) symmetric Hamiltonians. By exactly solving the non-Hermitian two-body problem of spin-1/2 (spin-1) bosons in a 3D harm...

[Phys. Rev. A 99, 063616] Published Wed Jun 19, 2019

]]>In this paper we study the thermal equilibration of small bipartite Bose-Hubbard systems, both quantum mechanically and in mean-field approximation. In particular we consider small systems composed of a single-mode “thermometer” coupled to a three-mode “bath,” with no additional environment acting o...

[Phys. Rev. A 99, 063617] Published Wed Jun 19, 2019

]]>Recent developments in real-time ultrafast measurement techniques have enabled us to prove experimentally that soliton molecules execute internal motions with some aspects similar to those of a matter molecule. Such an analogy between the dynamics of soliton molecules and the dynamics of matter mole...

[Phys. Rev. A 99, 063824] Published Wed Jun 19, 2019

]]>The perturbation theory by Ge *et al.* [Phys. Rev. A **87**, 023833 (2013)] for transverse-electric polarized modes in weakly deformed microdisks omits terms related to the variation of the normal derivative of the magnetic field along the boundary. Here, we show that these terms are necessary to accurate...

[Phys. Rev. A 99, 063825] Published Wed Jun 19, 2019

]]>Isolating past information relevant for future prediction is central to quantitative science. Quantum models offer a promising approach, enabling statistically faithful modeling while using less past information than any classical counterpart. Here we introduce a class of phase-enhanced quantum mode...

[Phys. Rev. A 99, 062110] Published Tue Jun 18, 2019

]]>Performances of work-to-work conversion are studied for a dissipative nonlinear quantum system with two isochromatic phase-shifted drives. It is shown that for weak Ohmic damping simultaneous maximization of efficiency with finite power yield and low power fluctuations can be achieved. Optimal perfo...

[Phys. Rev. A 99, 062111] Published Tue Jun 18, 2019

]]>We propose a scheme for covert active sensing using floodlight illumination from a terahertz-bandwidth amplified spontaneous emission (ASE) source and heterodyne detection. We evaluate the quantum-estimation-theoretic performance limit of covert sensing, wherein a transmitter's attempt to sense a ta...

[Phys. Rev. A 99, 062321] Published Tue Jun 18, 2019

]]>Quantum information and communication processing within quantum networks usually employ identical particles. Despite this, the physical role of the quantum statistical nature of particles in large-scale networks remains elusive. Here, we show that just the indistinguishability of fermions allows a n...

[Phys. Rev. A 99, 062322] Published Tue Jun 18, 2019

]]>In this work we demonstrate experimentally how generative model training can be used as a benchmark for small (fewer than five qubits) quantum devices. Performance is quantified using three data analytic metrics: the Kullback-Leibler divergence and two adaptations of the ${F}_{1}$ score. Using the $2\times 2$ bars...

[Phys. Rev. A 99, 062323] Published Tue Jun 18, 2019

]]>We report measurements of the electric dipole matrix elements of the ${}^{133}\mathrm{Cs}\phantom{\rule{0.16em}{0ex}}6s\phantom{\rule{0.16em}{0ex}}{}^{2}S_{1/2}\to 7p\phantom{\rule{0.16em}{0ex}}{}^{2}P_{1/2}$ and $6s\phantom{\rule{0.16em}{0ex}}{}^{2}S_{1/2}\to 7p\phantom{\rule{0.16em}{0ex}}{}^{2}P_{3/2}$ transitions. Each of these determinations is based on direct, precise comparisons of the absorption coefficients between two absorption lines. For the $\langle 6s\phantom{\rule{0.16em}{0ex}}{}^{2}S_{1/2}\left|\right|r\left|\right|7p\phantom{\rule{0.16em}{0ex}}{}^{2}P_{3/2}\rangle $ matrix element, w...

[Phys. Rev. A 99, 062510] Published Tue Jun 18, 2019

]]>We report the demonstration of a quasi-one-dimensional Stern-Gerlach effect on a supersonic beam of lithium-7 atoms. This method combines a pulsed magnetic field gradient plus a strong bias field to create a quasi-one-dimensional force. We discuss the application of this technique to a cooling metho...

[Phys. Rev. A 99, 063417] Published Tue Jun 18, 2019

]]>Numerical simulations of the rotational contribution of oxygen and nitrogen molecules to the Kerr refractive index change in air are performed for ultrashort laser pulses in the near- and mid-infrared wavelength region. The calculated molecular response is parametrized by means of a damped harmonic ...

[Phys. Rev. A 99, 063418] Published Tue Jun 18, 2019

]]>The studies of multimagnon excitations will extend our understandings of quantum magnetism and strongly correlated matters. Here, by using the time-evolving block decimation algorithm, we investigate the Bloch oscillations of two-magnon excitations under a gradient magnetic field. Through analyzing ...

[Phys. Rev. A 99, 063614] Published Tue Jun 18, 2019

]]>Chains of coupled two-level atoms behave as one-dimensional quantum spin systems, exhibiting free magnons and magnon bound states. While these excitations are well studied for closed systems, little consideration has been given to how they are altered by the presence of an environment. This will be ...

[Phys. Rev. A 99, 063615] Published Tue Jun 18, 2019

]]>We calculate the transmission spectrum of a superconducting circuit realization of the Dicke model and identify spectroscopic features that can serve as signatures of the superradiant phase. In particular, we calculate the resonance frequencies of the system as functions of the bias term, which is u...

[Phys. Rev. A 99, 063822] Published Tue Jun 18, 2019

]]>We address quantum state engineering of single- and two-mode states by means of nondeterministic noiseless linear amplifiers (NLAs) acting on Gaussian states. In particular, we consider the optimal implementation of a NLA proposed by Pandey *et al.* [Phys. Rev. A **88**, 033852 (2013)] and we show that it...

[Phys. Rev. A 99, 063823] Published Tue Jun 18, 2019

]]>The non-Markovian dynamics of a charged harmonic oscillator linearly coupled to a neutral bosonic heat bath is investigated in external uniform magnetic field. The analytical expression is derived for the asymptotic angular momentum. The orbital diamagnetism of quantum system in a dissipative enviro...

[Phys. Rev. A 99, 062109] Published Mon Jun 17, 2019

]]>In a recent series of works [Ebler *et al.*, Phys. Rev. Lett. **120**, 120502 (2018); arXiv:1809.06655v2; arXiv:1810.10457v2], it has been shown that the quantum superposition of causal order—the quantum switch—offers an enhancement of classical and quantum channel capacity through noisy channels, a phen...

[Phys. Rev. A 99, 062317] Published Mon Jun 17, 2019

]]>It is well known that the notions of spatial locality are often lost in quantum systems with long-range interactions, as exhibited by the emergence of phases with exotic long-range order and faster propagation of quantum correlations. We demonstrate here that such induced “quasinonlocal” effects do ...

[Phys. Rev. A 99, 062318] Published Mon Jun 17, 2019

]]>Quantum memories are an important building block for quantum information processing. Ideally, these memories preserve the quantum properties of the input. We present general criteria for measures to evaluate the quality of quantum memories. Then we introduce a quality measure based on coherence sati...

[Phys. Rev. A 99, 062319] Published Mon Jun 17, 2019

]]>Suppressing undesired nonunitary effects is a major challenge in quantum computation and quantum control. In this paper, by considering the adiabatic dynamics in the presence of a surrounding environment, we theoretically and experimentally analyze the robustness of adiabaticity in open quantum syst...

[Phys. Rev. A 99, 062320] Published Mon Jun 17, 2019

]]>Atomic lanthanum anion ${\mathrm{La}}^{-}$ is the best candidate for laser cooling of any atomic anions found so far. The bound-bound electric dipole transitions of ${\mathrm{La}}^{-}$ have been identified and measured. Theoretical studies have shown that ${\mathrm{La}}^{-}$ has a very complicated electronic structure, which cannot be well resolv...

[Phys. Rev. A 99, 062507] Published Mon Jun 17, 2019

]]>Sub-Doppler spectroscopy in alkali-metal vapor cells using two counterpropagating dual-frequency laser beams allows the detection of high-contrast sign-reversed natural-linewidth sub-Doppler resonances. Previously, a qualitative theory based on a simplified Λ-scheme model has been reported to explai...

[Phys. Rev. A 99, 062508] Published Mon Jun 17, 2019

]]>We predict the existence of a torque acting on an isotropic neutral nanosphere activated by a static magnetic field when the particle temperature differs from the surrounding vacuum. This phenomenon originates in time-reversal symmetry breaking of the particle interaction with the vacuum electromagn...

[Phys. Rev. A 99, 062509] Published Mon Jun 17, 2019

]]>We discuss the rotational cooling of diatomic molecules in a Bose-Einstein condensate (BEC) of ultracold atoms by emission of phonons with orbital angular momentum. Despite the superfluidity of the BEC there is no frictionless rotation for typical molecules since the dominant cooling occurs via emis...

[Phys. Rev. A 99, 062707] Published Mon Jun 17, 2019

]]>Alkali-metal-vapor magnetometers, using coherent precession of polarized atomic spins for magnetic-field measurement, have become one of the most sensitive magnetic-field detectors. Their application areas range from practical uses such as NMR signal detection to fundamental physics research such as...

[Phys. Rev. A 99, 063411] Published Mon Jun 17, 2019

]]>A three-state system subjected to a time-dependent Hamiltonian whose bare energies undergo one or more crossings, depending on the relevant parameters, is considered, also taking into account the role of dissipation in the adiabatic following of the Hamiltonian eigenstates. Depending on whether or n...

[Phys. Rev. A 99, 063412] Published Mon Jun 17, 2019

]]>Wigner time delay in photodetachment from the $3{p}_{3/2}$ and $3{p}_{1/2}$ subshells of ${\mathrm{Cl}}^{-}$ has been studied in the vicinity of the $2{p}_{3/2}$ and $2{p}_{1/2}$ thresholds, using the relativistic random phase approximation (RRPA). The results show time delay spectra dominated by many-body correlations along with very complic...

[Phys. Rev. A 99, 063413] Published Mon Jun 17, 2019

]]>We report on sawtooth-wave adiabatic-passage (SWAP) slowing of bosonic and fermionic dysprosium isotopes by using a 136-kHz-wide transition at 626 nm. A beam of precooled atoms is further decelerated in one dimension by the SWAP force and the amount of atoms at near zero velocity is measured. We dem...

[Phys. Rev. A 99, 063414] Published Mon Jun 17, 2019

]]>Manifestations of and possibilities related to vortex electrons in strong-field physics are discussed. We present a theory which extends the foundation of a powerful method of target structure and dynamics imaging to vortex electrons. The theory enables one to extract the differential cross section ...

[Phys. Rev. A 99, 063415] Published Mon Jun 17, 2019

]]>We report on measurements of the binding energies of several weakly bound vibrational states of the paramagnetic ${}^{174}\mathrm{Yb}{}^{6}\mathrm{Li}$ molecule in the electronic ground state using two-photon spectroscopy in an ultracold atomic mixture confined in an optical dipole trap. We theoretically analyze the experimental...

[Phys. Rev. A 99, 063416] Published Mon Jun 17, 2019

]]>We investigate the dimension of the phase-space attractor of a quantum chaotic many-body ratchet in the mean-field limit. Specifically, we explore a driven Bose-Einstein condensate in three distinct dynamical regimes—Rabi oscillations, chaos, and self-trapping regimes—and for each of them we calcula...

[Phys. Rev. A 99, 063609] Published Mon Jun 17, 2019

]]>Labouvie *et al.* [Phys. Rev. Lett. **116**, 235302 (2016)] have described an experiment with a weakly interacting Bose-Einstein condensate trapped in a one-dimensional optical lattice with localized loss created by a focused electron beam. We show that by setting suitable initial currents between neighbo...

[Phys. Rev. A 99, 063610] Published Mon Jun 17, 2019

]]>Coupled $XY$ model systems consisting of three-dimensional (3D) systems with disordered interlayer physics are of significant theoretical interest. We realize a set of coupled quasi-2D layers of ${}^{87}\mathrm{Rb}$ in the presence of disordered interlayer coupling. This is achieved with our high bandwidth arbitrary ...

[Phys. Rev. A 99, 063611] Published Mon Jun 17, 2019

]]>The absence of a characteristic momentum scale in the pseudopotential description of atomic interactions in ultracold (two-component Fermi) gases is known to lead to divergences in perturbation theory. Here we show that they also plague the calculation of the dynamics of the total energy following a...

[Phys. Rev. A 99, 063612] Published Mon Jun 17, 2019

]]>We show that the realization of synthetic magnetic fields via light-matter coupling in the $\mathrm{\Lambda}$ scheme implements a natural geometrical construction of magnetic fields, namely, as the pullback of the area element of the sphere to Euclidean space via certain maps. For suitable maps, this construction ge...

[Phys. Rev. A 99, 063613] Published Mon Jun 17, 2019

]]>We describe vacuum fluctuations and photon-field correlations in interacting quantum mechanical light-matter systems by generalizing the application of mixed quantum classical dynamics techniques. We employ the multitrajectory implementation of Ehrenfest mean-field theory, traditionally developed fo...

[Phys. Rev. A 99, 063819] Published Mon Jun 17, 2019

]]>We experimentally demonstrate the emergence of an azimuthally polarized vectorial vortex beam with a phase singularity upon Brewster reflection of focused circularly polarized light from a dielectric substrate. The effect originates from the polarizing properties of the Fresnel reflection coefficien...

[Phys. Rev. A 99, 063820] Published Mon Jun 17, 2019

]]>The analysis of single-mode photon fluctuations and their counting statistics at the superradiant phase transition is presented. The study concerns the equilibrium Dicke model in a regime where the Rabi frequency, related to a coupling of the photon mode with a finite-number qubit environment, plays...

[Phys. Rev. A 99, 063821] Published Mon Jun 17, 2019

]]>Recently, based on some quantum states which are locally irreducible in all bipartitions, strong quantum nonlocality has been presented by Halder *et al.* [Phys. Rev. Lett. **122**, 040403 (2019)]. However, the remaining questions are whether a set of quantum states can reveal strong quantum nonlocality w...

[Phys. Rev. A 99, 062108] Published Fri Jun 14, 2019

]]>The ability of an eavesdropper (Eve) to perform an intercept-resend attack on a free-space quantum-key-distribution (QKD) receiver by precisely controlling the incidence angle of an attack laser has been previously demonstrated. However, such an attack could be ineffective in the presence of atmosph...

[Phys. Rev. A 99, 062315] Published Fri Jun 14, 2019

]]>Quantum key distribution (QKD) offers a secret way to share keys between legitimate users which is guaranteed by the law of quantum mechanics. Most recently, the limitation of transmission distance without quantum repeaters was broken through by twin-field QKD [M. Lucamarini *et al.*, Nature (London)...

[Phys. Rev. A 99, 062316] Published Fri Jun 14, 2019

]]>We report a measurement of the valence orbital momentum profiles of tetrabromomethane (${\mathrm{CBr}}_{4}$) using symmetric noncoplanar $(e,2e)$ experiments at the impact energies of about 600 and 1200 eV. The experimental momentum profiles for the individual orbitals $5{t}_{1},13{t}_{2},5e,12{t}_{2}$, and $9{a}_{1}$ and the branching r...

[Phys. Rev. A 99, 062705] Published Fri Jun 14, 2019

]]>An important physical process unique to neutral-ion systems is the charge-transfer reaction. Here, we present measurements of and models for charge-transfer processes between cotrapped ultracold Ca atoms and Yb ions under well-controlled conditions. The theoretical analysis suggests the existence of...

[Phys. Rev. A 99, 062706] Published Fri Jun 14, 2019

]]>The Stark problem in quantum-confined geometries is challenging in high fields. In particular, the localization of electrons near sample boundaries is hard to accurately capture in perturbation methods. We analyze the problem for spherical quantum dots using a combination of numerical diagonalizatio...

[Phys. Rev. A 99, 063410] Published Fri Jun 14, 2019

]]>The dynamical properties of a one-dimensional system of two and three bosons escaping from an open potential well are studied in terms of the momentum distributions of particles. In the case of a two-boson system, it is shown that the single- and two-particle momentum distributions undergo a specifi...

[Phys. Rev. A 99, 063608] Published Fri Jun 14, 2019

]]>A uniform or periodic dielectric slab can serve as an optical waveguide for which guided modes are important, and it can also be used as a diffraction structure for which resonant modes with complex frequencies are relevant. Guided modes are normally studied below the lightline where they exist cont...

[Phys. Rev. A 99, 063818] Published Fri Jun 14, 2019

]]>High-order harmonic generation (HHG) in imperfect crystals, where the disorder is modeled by random shifts of the ionic positions, is studied using time-dependent density-functional theory. When irradiated by midinfrared laser pulses, the disorder-free system produces HHG spectra with two plateaus. ...

[Phys. Rev. A 99, 063408] Published Thu Jun 13, 2019

]]>Electron-ion coincidence experimental data obtained following argon $1s$ photoionization are reported. Slow photoelectrons were measured in coincidence with ${\mathrm{Ar}}^{+}$ and ${\mathrm{Ar}}^{2+}$ ions, and the $\beta $ angular distribution parameter was obtained. The measured beta parameter for the ${\mathrm{Ar}}^{2+}$-photoelectron coincidence meas...

[Phys. Rev. A 99, 063409] Published Thu Jun 13, 2019

]]>Recently, two independent experiments reported the observation of long-lived polarons in a Bose-Einstein condensate, providing an excellent setting to study the generic scenario of a mobile impurity interacting with a quantum reservoir. Here we expand the experimental analysis by disentangling the e...

[Phys. Rev. A 99, 063607] Published Thu Jun 13, 2019

]]>Indirect spin-spin interactions between nuclei bound in a molecule are well known in nuclear magnetic resonance, but such interactions between unbound atoms are less well studied and are often assumed to be zero. We present a precision calculation of this interaction between ${}^{129}\mathrm{Xe}$ and ${}^{3}\mathrm{He}$ nuclei in ...

[Phys. Rev. A 99, 060501(R)] Published Wed Jun 12, 2019

]]>This paper is devoted to the study of the Bayesian-inference approach in the context of estimating the dipole coupling strength in matter-field interactions. In particular, we consider the simplest model of a two-level system interacting with a single mode of the radiation field. Our estimation stra...

[Phys. Rev. A 99, 062106] Published Wed Jun 12, 2019

]]>Understanding how local potentials affect system eigenmodes is crucial for experimental studies of nontrivial bulk topology. Recent studies have discovered many exotic and highly nontrivial topological states in non-Hermitian systems. As such, it would be interesting to see how non-Hermitian systems...

[Phys. Rev. A 99, 062107] Published Wed Jun 12, 2019

]]>When a quantum system is divided into two local subsystems, measurements on the two subsystems can exhibit correlations beyond those possible in a classical joint probability distribution; these are partially explained by entanglement, and more generally by a wider class of measures such as the quan...

[Phys. Rev. A 99, 062313] Published Wed Jun 12, 2019

]]>For a bipartite entangled state shared by two observers, Alice and Bob, Alice can affect the postmeasured states left to Bob by choosing different measurements on her half. Alice can convince Bob that she has such an ability if and only if the unnormalized postmeasured states cannot be described by ...

[Phys. Rev. A 99, 062314] Published Wed Jun 12, 2019

]]>In the mean-field theory, the stabilization of polar chiral molecules is understood as a quantum phase transition where the mean-field ground state of molecules changes from the achiral eigenstate of the molecular Hamiltonian to one of the degenerated chiral states as the increase of the intermolecu...

[Phys. Rev. A 99, 062703] Published Wed Jun 12, 2019

]]>We present a combined experimental and theoretical study of the transmission of single charged 1-keV Ar ions through a cylindrical glass capillary of macroscopic dimensions. From quantitative measurements of the incoming and transmitted ion currents, combined with a detailed analysis, the amount of ...

[Phys. Rev. A 99, 062704] Published Wed Jun 12, 2019

]]>We investigate the thermal evolution of radio-frequency (RF) spectra of a spin-imbalanced Fermi gas near a Feshbach resonance in which degenerate Fermi-polaron and classical Boltzmann-gas regimes emerge in the low-temperature and high-temperature limits, respectively. By using self-consistent framew...

[Phys. Rev. A 99, 063606] Published Wed Jun 12, 2019

]]>We introduce a class of spiraling anomalous vortex beam (AVB) arrays in strongly nonlocal nonlinear media. The general analytical formula for the arrays is derived, and its propagation properties are analyzed. It is shown that the spiraling AVB arrays can present three different propagation states (...

[Phys. Rev. A 99, 063817] Published Wed Jun 12, 2019

]]>We describe and experimentally demonstrate a more practical three-party quantum secret sharing (QSS) protocol using polarization-entangled photon pairs. The source itself serves as an active participant and can switch between the required photon states by modulating the pump beam only, thereby makin...

[Phys. Rev. A 99, 062311] Published Tue Jun 11, 2019

]]>We discuss the problem of characterizing upper bounds on entanglement in a bipartite quantum system when only the reduced density matrices (marginals) are known. In particular, starting from the known two-qubit case, we propose a family of candidates for maximally entangled mixed states with respect...

[Phys. Rev. A 99, 062312] Published Tue Jun 11, 2019

]]>The electric dipole moment of the electron ($e\mathrm{EDM}$) and the scalar-pseudoscalar (S-PS) interaction are probes of new physics beyond the standard model of elementary particles, but experiments to observe them using atoms and molecules are still in progress. Molecules that have a large effective electri...

[Phys. Rev. A 99, 062506] Published Tue Jun 11, 2019

]]>The photon-electron angular-momentum transfer is intrinsic and overwhelmingly important in light-molecule interaction. However, the photon-nuclei angular-momentum transfer is seldom observed because of the very large inertial moment and the very small dipole of nuclei as compared to those of the ele...

[Phys. Rev. A 99, 063407] Published Tue Jun 11, 2019

]]>We study quantum quench dynamics in the Fermi-Hubbard model, and its $\mathrm{SU}\left(N\right)$ generalizations, in one-dimensional lattices in the limit of infinite onsite repulsion between all flavors. We consider families of initial states with generalized Néel order, namely, initial states in which there is a period...

[Phys. Rev. A 99, 063605] Published Tue Jun 11, 2019

]]>The vibronic dynamics of a trapped ion in the resolved-sideband regime can be described by the explicitly time-dependent nonlinear Jaynes-Cummings model. It is shown that the expectation value of the interaction Hamiltonian and its non-equal-time commutator can be determined by measuring the electro...

[Phys. Rev. A 99, 063816] Published Tue Jun 11, 2019

]]>A recently proposed quantum protocol for counterfactual communication [Y. Aharonov and L. Vaidman, Phys. Rev. A **99**, 010103(R) (2019)] relies on postselection to eliminate the weak trace in the transmission channel. We show that the postselection in this protocol additionally eliminates the flow of F...

[Phys. Rev. A 99, 060102(R)] Published Mon Jun 10, 2019

]]>The working substance fueling a quantum heat engine may contain coherence in its energy basis, depending on the dynamics of the engine cycle. In some models of quantum Otto heat engines, energy coherence has been associated with entropy production and quantum friction. We considered a quantum Otto h...

[Phys. Rev. A 99, 062103] Published Mon Jun 10, 2019

]]>We consider the problem of characterizing states of a multipartite quantum system from restricted, quasi-local information, with emphasis on uniquely determined pure states. By leveraging tools from dissipative quantum control theory, we show how the search for states consistent with an assigned lis...

[Phys. Rev. A 99, 062104] Published Mon Jun 10, 2019

]]>The exact statistics of an arbitrary quantum observable is analytically obtained. Due to the probabilistic nature of a sequence of intermediate measurements and stochastic fluctuations induced by the interaction with the environment, the measurement outcomes at the end of the system's evolution are ...

[Phys. Rev. A 99, 062105] Published Mon Jun 10, 2019

]]>Quantum annealing in a real device is necessarily susceptible to errors due to diabatic transitions and thermal noise. Nested quantum annealing correction is a method to suppress errors by using an all-to-all penalty coupling among a set of physical qubits representing a logical qubit. We show analy...

[Phys. Rev. A 99, 062307] Published Mon Jun 10, 2019

]]>We show how the efficiency of a logical Bell measurement (BM) can be calculated for arbitrary Calderbank-Shor-Steane (CSS) codes with the experimentally important constraint of using only transversal static linear-optical BMs on the physical single-photon qubit level. For this purpose, we utilize th...

[Phys. Rev. A 99, 062308] Published Mon Jun 10, 2019

]]>The recent direct experimental measurement of quantum entanglement paves the way towards a better understanding of many-body quantum systems and their correlations. Nevertheless, the experimental and theoretical advances had so far been predominantly limited to bosonic systems. Here, we study fermio...

[Phys. Rev. A 99, 062309] Published Mon Jun 10, 2019

]]>Coherence is a basic phenomenon in quantum mechanics and considered to be an essential resource in quantum information processing. Although the quantification of coherence has attracted a lot of interest, the lack of efficient methods to measure the coherence in experiments limits the applications. ...

[Phys. Rev. A 99, 062310] Published Mon Jun 10, 2019

]]>The hyperfine splitting of the ground state of selected B-like ions within the range of nuclear charge numbers $Z=49$–83 is investigated in detail. The rigorous QED approach together with the large-scale configuration-interaction Dirac-Fock-Sturm method are employed for the evaluation of the interelec...

[Phys. Rev. A 99, 062503] Published Mon Jun 10, 2019

]]>The Casimir force between two extended charge sources, embedded in a background of one-dimensional massive Dirac fermions, is explored by means of original contour integration techniques. For identical sources with the same (positive) charge, we find that in the nonperturbative region the Casimir in...

[Phys. Rev. A 99, 062504] Published Mon Jun 10, 2019

]]>We show that which-way interference within ringlike unit cells enhances the propagation of electronic excitations (excitons) along linear arrays made upon these basic units. After providing an analytic approximate solution of the eigenvalue problem for such aggregates, we show that the constructive ...

[Phys. Rev. A 99, 062505] Published Mon Jun 10, 2019

]]>A classical description of electron-emission differential ionization cross sections for highly charged high-velocity ions ($\sim 10$ a.u.) impinging on water molecules is presented. We investigate the validity of the classical statistical mechanics description of ionization ($\hslash =0$ limit of quantum mechanics...

[Phys. Rev. A 99, 062701] Published Mon Jun 10, 2019

]]>We report on experimental elastic differential and integral cross sections for electron scattering from zinc. The energy range of these measurements is 10–100 eV, while the scattered electron angular range in the differential cross-section data is ${10}^{\circ}\text{\u2013}{150}^{\circ}$. We also supplement our measured data with ...

[Phys. Rev. A 99, 062702] Published Mon Jun 10, 2019

]]>Photodissociation of ozone following absorption of biologically harmful solar ultraviolet radiation is the key mechanism for the life protecting properties of the atmospheric ozone layer. Even though ozone photolysis is described successfully by post-Hartree-Fock theory, it has evaded direct experim...

[Phys. Rev. A 99, 063405] Published Mon Jun 10, 2019

]]>Angular distribution of photoelectrons released by the ionization of randomly oriented molecules with two laser fields of carrier frequencies $\omega $ and $2\omega $, which are linearly polarized in two mutually orthogonal directions, is analyzed in the perturbation limit for the case of a one- versus two-photon i...

[Phys. Rev. A 99, 063406] Published Mon Jun 10, 2019

]]>The objective of this paper is the theoretical description of the Mott insulator to superfluid quantum phase transition of a Bose gas in an optical lattice. In former works the Rayleigh-Schrödinger perturbation theory was used within a mean-field approach, which yields partially nonphysical results ...

[Phys. Rev. A 99, 063603] Published Mon Jun 10, 2019

]]>The long-time existence of topologically nontrivial configurations of quantum vortices in the form of torus knots and links in trapped Bose-Einstein condensates is demonstrated numerically within the three-dimensional Gross-Pitaevskii equation with an external anisotropic parabolic potential. We ide...

[Phys. Rev. A 99, 063604] Published Mon Jun 10, 2019

]]>We report theoretical studies of adiabatic population transfer using dressed spin states. Quantum optimal control using the chopped random basis (CRAB) algorithm has been implemented in a negatively charged diamond nitrogen vacancy center that is coupled to a strong and resonant microwave field. We ...

[Phys. Rev. A 99, 063812] Published Mon Jun 10, 2019

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