Frequent measurements can modify the decay of an unstable quantum state with respect to the free dynamics given by Fermi's golden rule. In a landmark article [A. G. Kofman and G. Kurizki, Nature (London) **405**, 546 (2000)], Kofman and Kurizki concluded that in quantum decay processes, acceleration of ...

[Phys. Rev. A 97, 062122] Published Fri Jun 22, 2018

]]>Analyzing weak microwave signals in the GHz regime is a challenging task if the signal level is very low and the photon energy widely undefined. A superconducting qubit can detect signals in the low photon regime, but due to its discrete level structure, it is only sensitive to photons of certain en...

[Phys. Rev. A 97, 062334] Published Fri Jun 22, 2018

]]>Charge-exchange collisions of ${\mathrm{C}}^{6+}$ and ${\mathrm{O}}^{8+}$ ions with hydrogen and krypton atoms followed by radiative emissions are examined using the two-center basis generator method in the low- and intermediate-energy regimes. Capture cross sections are obtained within the independent-electron model and are used ...

[Phys. Rev. A 97, 062705] Published Fri Jun 22, 2018

]]>Time-resolved pump-probe measurements of Xe, pumped at 133 nm and probed at 266 nm, are presented. The pump pulse prepared a long-lived hyperfine wave packet in the Xe $5{p}^{5}\left({}^{2}P_{1/2}^{\circ}\right)6s{\phantom{\rule{0.16em}{0ex}}}^{2}{[1/2]}_{1}^{\circ}$ manifold ($E=77\phantom{\rule{0.16em}{0ex}}185\phantom{\rule{0.16em}{0ex}}{\mathrm{cm}}^{-1}=9.57\phantom{\rule{0.16em}{0ex}}\mathrm{eV}$). The wave packet was monitored via single-photon ionization and velocity map pho...

[Phys. Rev. A 97, 063417] Published Fri Jun 22, 2018

]]>We investigated both spatial and temporal profiles of the 420-nm yoked superfluorescence (YSF) from the atomic vapor of rubidium by driving the $5S-5D$ two-photon transition with an ultrashort laser pulse. By increasing the pump-pulse power beyond the saturation intensity, the spatial profile of the 4...

[Phys. Rev. A 97, 063418] Published Fri Jun 22, 2018

]]>The implementation of nonclassical light sources is becoming increasingly important for various quantum applications. A particularly interesting approach is to integrate such functionalities on a single chip as this could pave the way towards fully scalable quantum photonic devices. Several approach...

[Phys. Rev. A 97, 063844] Published Fri Jun 22, 2018

]]>We study optical Bloch oscillations in the one- and two-dimensional arrays of helical waveguides with transverse refractive index gradient. Longitudinal rotation of waveguides may lead to notable variations of the width of the band of quasienergies and even its complete collapse for certain radii of...

[Phys. Rev. A 97, 063845] Published Fri Jun 22, 2018

]]>We derive an exact computationally-efficient formula for the angular Schmidt spectrum of orbital angular momentum (OAM) entangled states produced by parametric down-conversion (PDC). Our formula yields the true spectrum and does not suffer from convergence issues arising due to infinite summations, ...

[Phys. Rev. A 97, 063846] Published Fri Jun 22, 2018

]]>The entangled quantum state spanned in a spatial domain is of special importance for fundamental research in quantum information. Previous experiments on spatial entanglement were individually studied on continuous variables of momentum and position bases and discrete variables of orbital-angular-mo...

[Phys. Rev. A 97, 063847] Published Fri Jun 22, 2018

]]>Four-photon stimulated Raman adiabatic passage–like (STIRAP-like) processes in the frame of the ${D}_{1}$ optical transition line of atomic ${}^{39}\mathrm{K}$ are investigated theoretically by means of a rigorous model that takes into account all the atomic states involved in the interaction with the pump and Stokes ligh...

[Phys. Rev. A 97, 063848] Published Fri Jun 22, 2018

]]>The goal of entanglement distillation is to turn a large number of weakly entangled states into a smaller number of highly entangled ones. Practical entanglement distillation schemes offer a trade-off between the fidelity to the target state and the probability of successful distillation. Exploiting...

[Phys. Rev. A 97, 062333] Published Thu Jun 21, 2018

]]>The clustering and drift properties of barium ions in xenon gas are explored theoretically, using density-functional theory and computational ion mobility theory, with the goal of better understanding barium ion transport for neutrinoless double beta decay. We derive the equilibrium conformations, e...

[Phys. Rev. A 97, 062509] Published Thu Jun 21, 2018

]]>Potential realization of a quantum thermometer operating in the nanokelvin regime, formed by a few-fermionic mixture confined in a one-dimensional harmonic trap, is proposed. Thermal states of the system are studied theoretically from the point of view of fundamental sensitivity to temperature chang...

[Phys. Rev. A 97, 063619] Published Thu Jun 21, 2018

]]>A strict mathematical framework combining perturbation theory and temporal coupled-mode theory is developed to model graphene-induced saturable absorption in graphene-enhanced nanophotonic resonators. To allow for loss saturation in graphene, a power-dependent model of its surface conductivity is ca...

[Phys. Rev. A 97, 063836] Published Thu Jun 21, 2018

]]>The possibility of observing nonclassical features in a physical system comprised of a cavity with two ensembles of two-level atoms has been investigated by considering different configurations of the ensembles with respect to the node and antinode of the cavity field under the framework of open qua...

[Phys. Rev. A 97, 063840] Published Thu Jun 21, 2018

]]>Nonlinear THz photonics is probably the last frontier of nonlinear optics. The strength of both the electric and the magnetic fields of these ultrashort low-frequency light bunches opens the way to exciting science and applications. Progress in the field though is slow because of the deficiency in s...

[Phys. Rev. A 97, 063842] Published Thu Jun 21, 2018

]]>The dispersive behavior of materials with atomic charge numbers varying from $Z=4$ (beryllium, Be) to $Z=82$ (lead, Pb) was investigated experimentally and theoretically at $\gamma $-ray energies up to 2 MeV. The experiment was performed at the double-crystal $\gamma $ spectrometer GAMS6 of the Institut Laue-Langevin i...

[Phys. Rev. A 97, 063843] Published Thu Jun 21, 2018

]]>For ${}^{229m}\mathrm{Th}$ isomer nucleus with an anomalously low nuclear excitation energy, ${E}^{\u2605}$ (currently accepted value of $7.8\pm 0.5\phantom{\rule{0.28em}{0ex}}\mathrm{eV}$), the bound internal conversion (BIC) decay process is caused by the excitation of a valence electron that is sensitive to the electronic structure of the atomic-sized neighborhood....

[Phys. Rev. A 97, 060503(R)] Published Wed Jun 20, 2018

]]>The operation of autonomous finite-time quantum heat engines relies on the existence of a stable limit cycle in which the dynamics becomes periodic. The two main questions that naturally arise are therefore whether such a limit cycle will eventually be reached and, once it has, what the state of the...

[Phys. Rev. A 97, 062121] Published Wed Jun 20, 2018

]]>Quantum network coding is an effective solution for alleviating bottlenecks in quantum networks. We introduce a measurement-based quantum network coding scheme for quantum repeater networks (MQNC), and analyze its behavior based on results acquired from Monte Carlo simulation that includes various e...

[Phys. Rev. A 97, 062328] Published Wed Jun 20, 2018

]]>Boson Sampling is the problem of sampling from the same output probability distribution as a collection of indistinguishable single photons input into a linear interferometer. It has been shown that, subject to certain computational complexity conjectures, in general the problem is difficult to solv...

[Phys. Rev. A 97, 062329] Published Wed Jun 20, 2018

]]>We probe dephasing mechanisms within a quantum network node consisting of a single nitrogen-vacancy center electron spin that is hyperfine coupled to surrounding ${}^{13}\mathrm{C}$ nuclear-spin quantum memories. Previous studies have analyzed memory dephasing caused by the stochastic electron-spin reset process, w...

[Phys. Rev. A 97, 062330] Published Wed Jun 20, 2018

]]>The Deutsch-Jozsa algorithm is one of the first examples of a quantum algorithm that is exponentially faster than any possible deterministic classical algorithm. It was proposed by Deutsch and Jozsa in 1992 with improvements by Cleve, Ekert, Macchiavello, and Mosca in 1998. The Deutsch-Jozsa problem...

[Phys. Rev. A 97, 062331] Published Wed Jun 20, 2018

]]>Magic states can be used as a resource to circumvent the restrictions due to stabilizer-preserving operations, and magic-state conversion has not been studied in the single-copy regime thus far. Here we solve the question of whether a stabilizer-preserving quantum operation exists that can convert b...

[Phys. Rev. A 97, 062332] Published Wed Jun 20, 2018

]]>Understanding electron-electron correlations in matter ranging from atoms to solids represents a grand challenge for both experiment and theory. These correlations occur on attosecond timescales and have only recently become experimentally accessible. In the case of highly excited systems, the task ...

[Phys. Rev. A 97, 062508] Published Wed Jun 20, 2018

]]>Attosecond interferometry relies on the application of a train of attosecond extreme-ultraviolet (XUV) pulses and a synchronized low-intensity infrared (IR) field to measure the dynamics of photoemission via the interference signal in the spectrum of emitted electrons. So far, all condensed-phase ex...

[Phys. Rev. A 97, 063415] Published Wed Jun 20, 2018

]]>We study the control of ionization dynamics of aligned ${\mathrm{N}}_{2}$ and ${\mathrm{O}}_{2}$ molecules in orthogonally polarized two-color (OTC) fields and calculate the photoelectron momentum distributions of molecules by solving the time-dependent Schrödinger equation and with a semiclassical model. In contrast with that of ...

[Phys. Rev. A 97, 063416] Published Wed Jun 20, 2018

]]>Properties of two interacting ultracold polar molecules trapped in a one-dimensional harmonic potential are studied with the quantum rigid-rotor model. The interplay of the molecular rotational structure, anisotropic dipolar interactions, spin-rotation coupling, electric and magnetic fields, and the harmonic trapping potential are examined in detail.

[Phys. Rev. A 97, 063618] Published Wed Jun 20, 2018

]]>We investigate the nonlinear propagation of multiterawatt femtosecond laser pulses at 800 nm wavelength in air, under different external focusing conditions. We profile the laser beam in the vicinity of the nonlinear focus using a technique based on the dependence of the single-shot ablation thresho...

[Phys. Rev. A 97, 063841] Published Wed Jun 20, 2018

]]>[Phys. Rev. A 97, 069904] Published Wed Jun 20, 2018

]]>In contrast to the ordinary spin Hall effect (SHE), which is a single-body phenomenon caused by the spin-orbit interaction (SOI), we propose a many-body SHE induced by the dipole-dipole interaction (DDI) between particles and demonstrate it in a system of ultracold magnetic atoms. While the SOI usua...

[Phys. Rev. A 97, 061608(R)] Published Tue Jun 19, 2018

]]>A theory of random-matrix bases is presented, including expressions for orthogonality, completeness, and the random-matrix synthesis of arbitrary matrices. This is applied to ghost imaging as the realization of a random-basis reconstruction, including an expression for the resulting signal-to-noise ...

[Phys. Rev. A 97, 062119] Published Tue Jun 19, 2018

]]>We investigate the gauge invariance of the dynamic (ac) Stark shift under “hybrid” gauge transformations from the “length” ($\stackrel{\u20d7}{E}\xb7\stackrel{\u20d7}{r}$) to the “velocity” ($\stackrel{\u20d7}{A}\xb7\stackrel{\u20d7}{p}$) gauge. By a “hybrid” gauge transformation, we understand a transformation in which the scalar and vector potentials are modified, but the wave ...

[Phys. Rev. A 97, 062120] Published Tue Jun 19, 2018

]]>The realization of high-fidelity quantum gates in a multiqubit system, with a typical target set at $99.9\%$, is a critical requirement for the implementation of fault-tolerant quantum computation. To reach this level of fidelity, one needs to carefully analyze the noises and imperfections in the exper...

[Phys. Rev. A 97, 062325] Published Tue Jun 19, 2018

]]>We introduce several classes of quantum combinatorial designs, namely quantum Latin squares, cubes, hypercubes, and a notion of orthogonality between them. A further introduced notion, quantum orthogonal arrays, generalizes all previous classes of designs. We show that mutually orthogonal quantum La...

[Phys. Rev. A 97, 062326] Published Tue Jun 19, 2018

]]>We introduce a general method for the construction of quasiprobability representations for arbitrary notions of quantum coherence. Our technique yields a non-negative probability distribution for the decomposition of any classical state. Conversely, quantum phenomena are certified in terms of signed...

[Phys. Rev. A 97, 062327] Published Tue Jun 19, 2018

]]>The impact of lossy multilayer structures on nonequilibrium atom-surface interactions is discussed. Specifically, the focus lies on a fully non-Markovian and nonequilibrium description of quantum friction, the fluctuation-induced drag force acting on an atom moving at constant velocity and height ab...

[Phys. Rev. A 97, 062507] Published Tue Jun 19, 2018

]]>We report the production of ultracold heteronuclear ${\mathrm{Cs}}^{*}\mathrm{Yb}$ molecules through one-photon photoassociation applied to an ultracold atomic mixture of Cs and Yb confined in an optical dipole trap. We use trap-loss spectroscopy to detect molecular states below the $\mathrm{Cs}\phantom{\rule{0.16em}{0ex}}\left({}^{2}P_{1/2}\right)+\mathrm{Yb}\left({}^{1}S_{0}\right)$ asymptote. For ${}^{133}\mathrm{Cs}\phantom{\rule{0.16em}{0ex}}{}^{\mathrm{1...}}\mathrm{Yb}$

[Phys. Rev. A 97, 063414] Published Tue Jun 19, 2018

]]>We study the lowest energy states for fixed total momentum, i.e., yrast states, of $N$ bosons moving on a ring. As in the paper of Syrwid and Sacha [Phys. Rev. A **92**, 032110 (2015)], we compare mean-field solitons with the yrast states, being the many-body Lieb-Liniger eigenstates. We show that even in...

[Phys. Rev. A 97, 063617] Published Tue Jun 19, 2018

]]>We demonstrate laser cooling and magneto-optical trapping of europium. The atoms are optically pumped to a metastable state and then loaded from an atomic-beam source via conventional Zeeman slowing and magneto-optical trapping techniques using a $J=13/2\leftrightarrow J=15/2$ quasicyclic transition. The trapped pop...

[Phys. Rev. A 97, 061607(R)] Published Mon Jun 18, 2018

]]>Light scattering in dense media is a fundamental problem of many-body physics, which is also relevant for the development of optical devices. In this work we investigate experimentally light propagation in a dense sample of randomly positioned resonant scatterers confined in a layer of subwavelength...

[Phys. Rev. A 97, 061801(R)] Published Mon Jun 18, 2018

]]>According to the world view of macrorealism, the properties of a given system exist prior to and independent of measurement, which is incompatible with quantum mechanics. Leggett and Garg put forward a practical criterion capable of identifying violations of macrorealism, and so far experiments perf...

[Phys. Rev. A 97, 062117] Published Mon Jun 18, 2018

]]>Zero-field nuclear magnetic resonance (NMR) has been recently developed as a complementary tool for nondestructive structural investigations of matter. However, precise and efficient control in such systems is still at the beginning. Based on the controllability of spin systems, we theoretically stu...

[Phys. Rev. A 97, 062118] Published Mon Jun 18, 2018

]]>We aim to perform direct optical spectroscopy of the ${}^{229}\mathrm{Th}$ nuclear isomer to measure its energy and lifetime, and to demonstrate optical coupling to the nucleus. To this end, we develop ${}^{229}\mathrm{Th}$-doped ${\mathrm{CaF}}_{2}$ crystals, which are transparent at the anticipated isomer wavelength. Such crystals are illuminat...

[Phys. Rev. A 97, 062506] Published Mon Jun 18, 2018

]]>Electron momentum spectroscopy (EMS) results are presented for the sulfur hexafluoride (${\mathrm{SF}}_{6}$) molecule using a high-resolution binary ($e$, $2e$) spectrometer at incident energies (${E}_{i}$) of 600, 1200, and 2400 eV plus the binding energy. The valence orbital momentum profiles were measured with a binding en...

[Phys. Rev. A 97, 062704] Published Mon Jun 18, 2018

]]>We revisit the Floquet-Bloch eigenstates of a one-dimensional electron gas in the presence of the periodic Kronig-Penney potential and an oscillating electric field. Considering the appropriate boundary conditions for the wave function and its derivative, we derive the determining equations for the ...

[Phys. Rev. A 97, 063413] Published Mon Jun 18, 2018

]]>We report an alternate formulation of the quantum master equation (QME) to describe the dynamics of a quantum system weakly coupled to a heat bath, in the presence of weak external driving. A key feature of this approach is the introduction of an explicit Hamiltonian to model the thermal fluctuation...

[Phys. Rev. A 97, 063837] Published Mon Jun 18, 2018

]]>Here we create an effective electric field force for photon in a synthetic frequency lattice to control the spectrum of light. The frequency lattice is created based on an optical waveguide modulator in which the dynamic index modulation can induce photonic transitions between adjacent lattice sites...

[Phys. Rev. A 97, 063838] Published Mon Jun 18, 2018

]]>We study terahertz (THz) emission by two-color femtosecond filaments in air using pump wavelengths ${\lambda}_{0}$ from 0.8 to 10.6 $\mu \mathrm{m}$. Comprehensive three-dimensional numerical simulations show that tens-of-centimeter long filaments created by a 10.6-$\mu \mathrm{m}$ pump pulse can produce mJ energy yields and GV/m field str...

[Phys. Rev. A 97, 063839] Published Mon Jun 18, 2018

]]>It is a central question in quantum thermodynamics to determine how irreversible is a process that transforms an initial state $\rho $ to a final state $\sigma $ and whether such irreversibility can be thought of as a useful resource. For example, we might ask how much work can be obtained by thermalizing $\rho $ to a ...

[Phys. Rev. A 97, 062114] Published Fri Jun 15, 2018

]]>When a photon passes through an interferometer, quantum mechanics does not provide a clear answer as to its past. Quantum retrodiction is a quantitative theory, which endeavors to make statements about the past of a system based on present knowledge. Quantum retrodiction may be used to analyze the p...

[Phys. Rev. A 97, 062115] Published Fri Jun 15, 2018

]]>Interference is at the heart of quantum mechanics and is most intriguing in the complexity of multiple interfering particles. Here fundamental symmetry considerations are used to develop a general formalism for understanding the totally destructive interference of many bosons and fermions.

[Phys. Rev. A 97, 062116] Published Fri Jun 15, 2018

]]>Solving the Toeplitz systems, which involves finding the vector $x$ such that ${T}_{n}x=b$ given an $n\times n$ Toeplitz matrix ${T}_{n}$ and a vector $b$, has a variety of applications in mathematics and engineering. In this paper, we present a quantum algorithm for solving the linear equations of Toeplitz matrices, in whic...

[Phys. Rev. A 97, 062322] Published Fri Jun 15, 2018

]]>Standard randomized benchmarking protocols entail sampling from a unitary 2-design, which is not always practical. In this article we examine randomized benchmarking protocols based on subgroups of the Clifford group that are not unitary 2-designs. We introduce a general method for analyzing such pr...

[Phys. Rev. A 97, 062323] Published Fri Jun 15, 2018

]]>We show that bipartite entanglement in an one-dimensional quantum spin model undergoing time evolution due to local Markovian environments can be frozen over time. We demonstrate this by using a number of paradigmatic quantum spin models including the anisotropic $XY$ model in the presence of a unifor...

[Phys. Rev. A 97, 062324] Published Fri Jun 15, 2018

]]>High-order harmonic generation in graphene driven by the elliptically polarized midinfrared driving pulse is theoretically investigated by solving the two-band semiconductor Bloch equation in the Houston basis under the tight-binding approximation. It is found that the maximal harmonic yield occurs ...

[Phys. Rev. A 97, 063412] Published Fri Jun 15, 2018

]]>We present analytical results for the nonlocal pair correlations in one-dimensional bosonic systems with repulsive contact interactions that are uniformly valid from the classical regime of high temperatures down to weak quantum degeneracy entering the regime of ultralow temperatures. By using the i...

[Phys. Rev. A 97, 063612] Published Fri Jun 15, 2018

]]>An efficient scheme to image freely propagating ${}^{6}$Li atoms with spin and position resolution is presented. Combined with time of flight, it enables the measurement of single-particle momenta.

[Phys. Rev. A 97, 063613] Published Fri Jun 15, 2018

]]>The Wigner function is studied for trapped noninteracting fermions. Universal scaling behavior of the function, independent of the trapping potential and the spatial dimension, is found at both zero and finite temperatures.

[Phys. Rev. A 97, 063614] Published Fri Jun 15, 2018

]]>When the spectrum of magnetic excitations of a quantum mixture is much softer than the density spectrum, the system becomes effectively incompressible and can host magnetic defects. These are characterized by the presence of a topological defect in one of the two species and by a local modification ...

[Phys. Rev. A 97, 063615] Published Fri Jun 15, 2018

]]>We consider the system of dimers formed in a one-dimensional mass-balanced Bose-Bose mixture of species $\sigma =\uparrow ,\downarrow $ with attractive interspecies and repulsive intraspecies contact interactions. In the plane parametrized by the ratios of the coupling constants ${g}_{\uparrow \uparrow}/\left|{g}_{\uparrow \downarrow}\right|$ and ${g}_{\downarrow \downarrow}/\left|{g}_{\uparrow \downarrow}\right|$ we trace out the curve...

[Phys. Rev. A 97, 063616] Published Fri Jun 15, 2018

]]>It has been recently proposed that single molecule spectroscopy could be employed to detect the motion of nanomechanical resonators. Estimates of the coupling constant ($g$) between the molecular two-level system and the oscillator indicate that it can reach values much larger than the mechanical reso...

[Phys. Rev. A 97, 063833] Published Fri Jun 15, 2018

]]>Emission of electromagnetic radiation by accelerated particles with electric, toroidal, and anapole dipole moments is analyzed. It is shown that ellipticity of the emitted light can be used to differentiate between electric and toroidal dipole sources and that anapoles, elementary neutral nonradiati...

[Phys. Rev. A 97, 063834] Published Fri Jun 15, 2018

]]>Spectral broadening of ultrashort laser pulses is simultaneously described by either self-phase modulation (SPM) or four-wave mixing (FWM). The latter implies the instantaneous conservation of both the photon number and energy, while the former describes a time-dependent frequency shift, implying a ...

[Phys. Rev. A 97, 063835] Published Fri Jun 15, 2018

]]>Three research groups have solved the three-body problem for bosons confined in a one-dimensional system.

[Phys. Rev. A 97, 061603(R)] Published Thu Jun 14, 2018

]]>Three research groups have solved the three-body problem for bosons confined in a one-dimensional system.

[Phys. Rev. A 97, 061604(R)] Published Thu Jun 14, 2018

]]>Three research groups have solved the three-body problem for bosons confined in a one-dimensional system.

[Phys. Rev. A 97, 061605(R)] Published Thu Jun 14, 2018

]]>Far out-of-equilibrium many-body quantum dynamics in isolated systems necessarily generates interferences beyond an Ehrenfest timescale, where quantum and classical expectation values diverge. Of great recent interest is the role these interferences play in the spreading of quantum information acros...

[Phys. Rev. A 97, 061606(R)] Published Thu Jun 14, 2018

]]>Most experimental protocols for measuring scrambling require time evolution with a Hamiltonian and with the Hamiltonian's negative counterpart (backward time evolution). Engineering controllable quantum many-body systems for which such forward and backward evolution is possible is a significant expe...

[Phys. Rev. A 97, 062113] Published Thu Jun 14, 2018

]]>The relativistic multiconfiguration Dirac-Hartree-Fock and the nonrelativistic multiconfiguration Hartree-Fock methods have been employed to calculate the magnetic dipole and electric quadrupole hyperfine structure constants of zinc. The calculated electric field gradients for the $4s4p\phantom{\rule{0.16em}{0ex}}\phantom{\rule{0.16em}{0ex}}{}^{3}P_{1}^{o}$ and $4s4p\phantom{\rule{0.16em}{0ex}}\phantom{\rule{0.16em}{0ex}}P_{\mathrm{...}}$

[Phys. Rev. A 97, 062505] Published Thu Jun 14, 2018

]]>The processes of energy gain and redistribution in a dense gas subject to an intense ultrashort laser pulse are investigated theoretically for the case of high-pressure argon. The electrons released via strong-field ionization and driven by an oscillating laser field collide with neutral neighbor at...

[Phys. Rev. A 97, 063411] Published Thu Jun 14, 2018

]]>We report on electromagnetic modes in space-time-modulated dispersion-engineered media. These modes exhibit unusual dispersion relation, field profile, and scattering properties. They are generated by coupled codirectional space-time harmonic pairs and occur in space-time periodic media whose consti...

[Phys. Rev. A 97, 063829] Published Thu Jun 14, 2018

]]>We theoretically revisit the problem of the propagation of coherent light pulses through a linear medium when the carrier frequency of the pulses coincides with the minimum of a narrow dip in the medium transmission. Considering realistic contrasts between the maximum and minimum transmission of the...

[Phys. Rev. A 97, 063830] Published Thu Jun 14, 2018

]]>We show that it is possible to independently control both the trajectory and the maximum amplitude along the trajectory of a paraxial accelerating beam. This is accomplished by carefully engineering both the amplitude and the phase of the beam on the input plane. Furthermore, we show that the width ...

[Phys. Rev. A 97, 063831] Published Thu Jun 14, 2018

]]>A method to measure decoherence in an optomechanical system is developed. The scheme overcomes previous limitations, promising a route to observe the quantum to classical transition in macroscopic systems.

[Phys. Rev. A 97, 063832] Published Thu Jun 14, 2018

]]>A discrete-time quantum walk (QW) is essentially an operator driving the evolution of a single particle on the lattice, through local unitaries. Some QWs admit a continuum limit, leading to well-known physics partial differential equations, such as the Dirac equation. We show that these simulation r...

[Phys. Rev. A 97, 062111] Published Wed Jun 13, 2018

]]>We introduce an analytically treatable discrete time quantum walk in a one-dimensional lattice which combines non-Markovianity and hyperballistic diffusion associated with a Gaussian whose variance ${\sigma}_{t}^{2}$ grows cubicly with time $\sigma \propto {t}^{3}$. These properties have have been numerically found in several systems...

[Phys. Rev. A 97, 062112] Published Wed Jun 13, 2018

]]>The while-you-wait computing paradigm combines elements of digital and analog quantum computation with the aim of minimizing the need of external control. In this architecture the computer is split into logic units, each continuously implementing a single recurring multigate operation via the unmodu...

[Phys. Rev. A 97, 062321] Published Wed Jun 13, 2018

]]>The electromagnetic Casimir interaction between two spheres is studied within the scattering approach using the plane-wave basis. It is demonstrated that the proximity force approximation (PFA) corresponds to the specular-reflection limit of Mie scattering. Using the leading-order semiclassical WKB ...

[Phys. Rev. A 97, 062504] Published Wed Jun 13, 2018

]]>The charge-state dynamics of the nitrogen-vacancy (NV) center in diamond play a key role in a wide range of applications, yet remain imperfectly understood. Using single picosecond pulses and pulse pairs, we quantitatively investigate the charge dynamics associated with excitation and fluorescence d...

[Phys. Rev. A 97, 063408] Published Wed Jun 13, 2018

]]>The role of the Coulomb potential of the atomic core for the creation of caustics in the photoelectron momentum distribution for tunneling ionization in a linearly polarized strong laser field, commonly termed Coulomb focusing, is investigated within classical theory beyond the dipole approximation....

[Phys. Rev. A 97, 063409] Published Wed Jun 13, 2018

]]>An analytical method for treating Coulomb focusing in strong-field ionization in a linearly polarized laser field has been proposed in the first paper of this series, where analytical formulas have been derived for the Coulomb momentum transfer to the tunneled electron at the tunnel exit and due to ...

[Phys. Rev. A 97, 063410] Published Wed Jun 13, 2018

]]>We study quasi-two-dimensional dipolar Bose-Einstein condensates, in which the Bogoliubov excitation spectrum displays, at sufficiently large gas density, a deep roton minimum due to the spatially anisotropic behavior of the dipolar two-body potential. A rapid quench, performed on the speed of sound...

[Phys. Rev. A 97, 063611] Published Wed Jun 13, 2018

]]>Wave scattering from two-dimensional self-affine Dirichlet and Neumann surfaces is studied for the purpose of using the intensity scattered from them to obtain the Hurst exponent and topothesy that characterize the self-affine roughness. By the use of the Kirchhoff approximation, a closed-form mathe...

[Phys. Rev. A 97, 063825] Published Wed Jun 13, 2018

]]>Many quantum advantages in metrology and communication arise from interferometric phenomena. Such phenomena can occur on ultrafast timescales, particularly when energy-time entangled photons are employed. These have been relatively unexplored as their observation necessitates time resolution much sh...

[Phys. Rev. A 97, 063826] Published Wed Jun 13, 2018

]]>Wolf effect refers to a spectral shift of light during its propagation even in free space, which results from the fluctuating (or correlation) nature of light sources. In conventional optics, the propagation laws of light are usually considered in flat space. However, optical phenomena are fascinati...

[Phys. Rev. A 97, 063827] Published Wed Jun 13, 2018

]]>We investigate theoretically the mode splitting induced by an arbitrarily shaped Rayleigh scatterer attached to a whispering-gallery microcavity. The information including polar position, orientation, and polarizability tensor of the nanoparticle can be obtained through the mode-splitting signal. It...

[Phys. Rev. A 97, 063828] Published Wed Jun 13, 2018

]]>We consider Landau damping of elementary excitations in Bose-Einstein condensates (BECs) with dipolar interactions. We discuss quantum and quasiclassical regimes of Landau damping. We use a generalized wave-kinetic description of BECs which, apart from the long-range dipolar interactions, also takes...

[Phys. Rev. A 97, 063610] Published Tue Jun 12, 2018

]]>We apply the formalism of quantum estimation theory to obtain information about the value of the nonlinear optomechanical coupling strength. In particular, we discuss the minimum mean-square error estimator and a quantum Cramér–Rao-type inequality for the estimation of the coupling strength. Our est...

[Phys. Rev. A 97, 063821] Published Tue Jun 12, 2018

]]>A special kind of degeneracy, known as exceptional points (EPs), for resonant states on a dielectric periodic slab are investigated. Due to their unique properties, EPs have found important applications in lasing, sensing, unidirectional operations, etc. In general, EPs may appear in non-Hermitian e...

[Phys. Rev. A 97, 063822] Published Tue Jun 12, 2018

]]>Engineering and harnessing coherent excitonic transport in organic nanostructures has recently been suggested as a promising way towards improving manmade light-harvesting materials. However, realizing and testing the dissipative system-environment models underlying these proposals is presently very...

[Phys. Rev. A 97, 063823] Published Tue Jun 12, 2018

]]>Recently, a series of theoretical and experimental papers on free-space propagation of pulsed Laguerre-Gaussian and Bessel beams was published, which reached contradictory and controversial results about group velocities of such pulses. Depending on the measurement scheme, the group velocity can be ...

[Phys. Rev. A 97, 063824] Published Tue Jun 12, 2018

]]>[Phys. Rev. A 97, 069903] Published Tue Jun 12, 2018

]]>The one-shot $GW$ method, beginning with the local density approximation (LDA), enables one to calculate photoemission and inverse photoemission spectra. In order to calculate photoabsorption spectra, one had to additionally solve the Bethe-Salpeter equation (BSE) for the two-particle (electron-hole) ...

[Phys. Rev. A 97, 060502(R)] Published Mon Jun 11, 2018

]]>We examine distinct measures of fermionic entanglement in the exact ground state of a finite superconducting system. It is first shown that global measures such as the one-body entanglement entropy, which represents the minimum relative entropy between the exact ground state and the set of fermionic...

[Phys. Rev. A 97, 062109] Published Mon Jun 11, 2018

]]>We present an approach to the problem of quantization of the damped harmonic oscillator. To start with, we adopt the standard method of doubling the degrees of freedom of the system (Bateman form) and then, by introducing some new parameters, we get a generalized coupled set of equations from the Ba...

[Phys. Rev. A 97, 062110] Published Mon Jun 11, 2018

]]>Channel capacities of quantum channels can be nonadditive even if one of two quantum channels has no channel capacity. We call this phenomenon *activation* of the channel capacity. In this paper, we show that when we use a quantum channel on a qubit system, only a noiseless qubit channel can generate ...

[Phys. Rev. A 97, 062314] Published Mon Jun 11, 2018

]]>Universal quantum computation using photonic systems requires gates the Hamiltonians of which are of order greater than quadratic in the quadrature operators. We first review previous proposals to implement such gates, where specific non-Gaussian states are used as resources in conjunction with enta...

[Phys. Rev. A 97, 062315] Published Mon Jun 11, 2018

]]>Rapid preparation, manipulation, and correction of spin states with high fidelity are requisite for quantum information processing and quantum computing. In this paper, we propose a fast and robust approach for controlling two spins with Heisenberg and Ising interactions. By using the concept of sho...

[Phys. Rev. A 97, 062317] Published Mon Jun 11, 2018

]]>By coupling a $\mathrm{\Lambda}$-type quantum emitter to a chiral waveguide, in which the polarization of a photon is locked to its propagation direction, we propose a controllable photon-emitter interface for quantum networks. We show that this chiral system enables the swap gate and a hybrid-entangling gate betwee...

[Phys. Rev. A 97, 062318] Published Mon Jun 11, 2018

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