Multipartite quantum steering has important application in quantum information processing. Here we study the influence of thermal noise on the collective quantum steering and genuine tripartite steering in a system of four-level inverted Y-type atoms, in which the atomic coherence is initially prepared and the cavity is coupled to a thermal reservoir. It is found that for the cases of the balanced

We report measurements of low energy positron scattering from neon, with the first measurements of absolute differential cross sections (DCSs) and of state-selective electronic excitation. These measurements are compared to calculations using the relativistic optical potential (ROP) technique, as well as other recently published theoretical calculations. At the lowest energies, experimental DCS data

Electron-induced triple differential cross sections (TDCSs) have been obtained for the few outer sub-shells of tungsten atoms, namely W (6s), W (5d), W (5p) and W (4f). Tungsten and related materials have been recommended as the prime candidates for wall materials in fusion plasma devices. The electron-induced cross-section data are strongly required for the diagnostics and modeling of plasma in such

We present excitation cross sections in collision between two ground state hydrogen atoms using a four-body classical trajectory Monte Carlo model. Calculations were performed for impact energies in the range between 1.0 keV and 100 keV where the cross sections are highly relevant to the interest of the fusion research. Beside the total excitation cross sections for target and projectile we also present

The position and momentum probability densities of a multidimensional quantum system are fully characterized by means of the radial expectation values ⟨r α ⟩ and , respectively. These quantities, which describe and/or are closely related to various fundamental properties of realistic systems, have not been calculated in an analytical and effective manner up until now except for a number of three-dimensional

Binding energies, oscillator strengths, and polarizabilities of hydrogen-like atoms embedded in dense quantum plasmas are calculated in high precision by employing the generalized pseudospectral method. Benchmark predictions of these quantities are obtained for both the ground and excited states including high-order transitions. The critical behaviour of system eigenenergies, radial mean values, oscillator

We theoretically investigate the high-order harmonic generation (HHG) driven by dual-pulse lasers. The first pulse of 800nm can create plasma in the high-density gas target. Then, the second pulse of 1800nm is spatiotemporally reshaped by the plasma and generates soft x-ray high-order harmonics in the overdriven regime. The simulation results show that adding the first pulse can promote the phase matching

Hamiltonian estimation is a cardinal task in applications of quantum metrology, quantum computation, quantum simulation, etc. When the evolution time is short in order to suppress noise and enhance sensitivity, the measurement and postprocessing may incur high cost. In this paper, we propose an adaptive weak measurement scheme for Hamiltonian estimation, which adjusts the pre- and post-selection according

We present a scheme that enables the observation of interference effects in the resonance fluorescence of a V-type atom with orthogonal dipole moments. Specifically, we consider the atomic configuration of a J g = 0 to J e = 1 transition driven by a single laser field. By employing polarization-sensitive detection in such a way that the light emitted on the two transitions become indistinguishable

We demonstrate laser interferometry based on phase difference between the two arms of an interferometer. The experiments are done with a Cs atomic vapor cell at room temperature and use atomic coherence. The interference can be tuned from constructive to destructive by tuning the relative phase between the two arms. It is similar to the Michelson interferometer, but differs in the important aspect

Positron impact scattering cross-sections (CS) like elastic differential, integral and momentum transfer of acetone are reported in the energy range from 0.1 eV to a few keV using a cc-pVTZ basis set within single centre expansion formalism. The optimized molecular wavefunction of the target was obtained from the multi-center expansion of the Gaussian-type orbitals within a Hartree–Fock self consistent

We report an experimental study of the electron-impact ionization (E 0 = 65eV) and fragmentation of carbon dioxide clusters for the formation of and using a reaction microscope. All three charged particles, two outgoing electrons and one cation, are detected in coincidence such that the momentum vectors and, consequently, the kinetic energies for these final-state particles are determined. The reaction

It has been established that the proton transfer dynamics of play an important role in determining the chain reaction of phosphorus-containing compounds in the planetary ionosphere. This work presents an accurate global potential energy surface (PES) of for the first time by fitting extensive ab initio energies from the aug-cc-pV(T, Q)Z level of theory using the multi-reference configuration interaction

Bichromatic extreme-ultraviolet pulses from a seeded free-electron laser enable us to measure photoelectron angular distribution (PAD) as a function of the relative phase between the different wavelength components. The time-dependent multiconfiguration self-consistent-field (TD-MCSCF) methods are powerful multielectron computation methods to accurately simulate such photoionization dynamics from the

In this reply, we address the comments made by A N Ryabtsev on our paper (H Lu etal 2020 J. Phys. B: At. Mol. Opt. Phys. 53 115001). Specifically, we emphasize that the observed spectra depend critically on the plasma source type and conditions that pertain in the source. Our source of ions and experimental setup/method are quite different to the one referred to in the comment (A N Ryabtsev etal 2000

Infinite quasiperiodic arrangements in space, such as quasicrystals, are typically described as projections of higher-dimensional periodic lattices onto the physical dimension. The concept of a reference higher-dimensional space, called a superspace, has proved useful in relation to quasiperiodic systems. Although some quantum-mechanical systems in quasiperiodic media have been shown to admit quasiperiodic

Penning ionisation (PI) processes involving pairs of Rydberg alkali-metal atoms, excited to different quantum states and experiencing dipole–dipole interactions, have a wide range of important properties in atomic physics. Within the framework of the semiclassical approximation, we have used both numerical and analytical approaches to examine the Penning autoionisation width dependence on the state

Using the singles and doubles approximated relativistic coupled-cluster method, we calculate hyperfine-structure constant A and B of 24 low-lying states of La2+. The results of the lowest four states 5d 3/2,5/2 and 4f 5/2,7/2 are compared with recently measured values (Olmschenk etal 2017 Phys. Rev. A 96 032502). Reasonable agreement is found for hyperfine-structure constant A of 5d 3/2 and 4f 5/2

We present new sum rules for 3jm coefficients, which involve, in addition to the usual weighting factor (2j + 1) where j is an angular momentum, the quantity [j(j + 1)] k with k ⩾ 1. The sum rules appear for instance in the statistical modeling of rotational spectra within the theory of moments, and enable one to deduce the expectation values of r k (used in the theory of Stark effect for hydrogenic

The direct and resonant single-photon photoionization of W63+ ions from their ground state 1s 22s 22p 63s 2 S 1/2 and four lowly-excited states 1s 22s 22p 63p 2 P 1/2,3/2 and 1s 22s 22p 63d 2 D 3/2,5/2 has been studied within the framework of the relativistic R-matrix method and the multiconfigurational Dirac–Fock method. Special attention has been paid to obtaining direct and resonant ionization limits

A higher-order parametric down-conversion (PDC) photon state is amazingly different from the states involving independent photon pairs. We focus on the third-order PDC photons. Firstly, we present a symmetry detector which is capable of analyzing twin-beam six-photon symmetric states in the regime of weak nonlinearities. By cascading symmetry detectors, then, it is shown that one can generate third-order

It is shown that the photoabsorption spectra of Pb II and Bi III reported by Lu etal (2020 J. Phys. B: At. Mol. Opt. Phys. 53 115001) can be almost fully explained by photoabsorption from the levels of the ground state configuration with little reference to the photoabsorption from the levels of the excited configurations.

We present an approach to achieve bi-directional conversion between microwave and optical photons based on a hybrid waveguide-QED structure. The proposed converter combines both the merits of optomechanical system and superconducting circuits. Through analysis, we obtain two different impedance matching conditions to realize an ideal conversion efficiency close to unity. One of the matching conditions

In this work, we explore systematically various SO(2)-rotation-induced multiple dark–dark (DD) soliton breathing patterns obtained from stationary and spectrally stable multiple dark–bright (DB) and DD waveforms in trapped one-dimensional, two-component atomic Bose–Einstein condensates. The stationary states stemming from the associated linear limits (as the eigenfunctions of the quantum harmonic oscillator

We study phase-dependent fluctuations of the resonance fluorescence of a single Λ-type three-level atom in the regime near coherent population trapping, i.e. alongside the two-photon detuning condition. To this end, we employ the method of conditional homodyne detection (CHD) which considers squeezing in the weak driving regime, and extends to non-Gaussian fluctuations for saturating and strong fields

Tunable diode laser induced fluorescence (TDLIF) measurements are discussed and quantitatively evaluated for nitrogen admixtures in argon plasma under the influence of a strong magnetic field. TDLIF measurements were used to evaluate light-transport properties in a strongly magnetized optically thick argon/nitrogen plasma under different pressure conditions. Therefore, a coupled system of rate balance

We study the non-equilibrium dynamics of two coupled oscillators interacting with their own heat baths of quantum scalar fields at different temperature T 1 and T 2 with bilinear couplings between them. We particularly focus on the entanglement or inseparability property of their quantum states. The critical temperatures of two respective oscillators, T 1c and T 2c, higher than which the entanglement

We theoretically demonstrate the characteristics of an output probe field by considering a set of four mirrors that form a cavity system. In a set of four mirrors, two are fixed while two are moveable and each is driven by an external pump field. Each oscillatory mirror has an external plate (mirror) which can generate a Casimir force (CF). The two CFs affect the radiation pressure inside the cavity

Static Casimir effect as one of the most interesting purely quantum effects is very general and may bring about novel physical phenomena and find applications in various fields of physics. Here, we investigate theoretically the generation of optical chaos induced by the static Casimir effect in an optomechanical system. We show that the dynamic behavior of the cavity field experiences the conversion

Here we propose a scheme to realize phonon blockade in a cascaded coupling optomechanical system, where a quadratically coupled optomechanical system couples with a mechanical oscillator. The strong nonlinear interaction between photons and phonons in the quadratically coupled optomechanical system is induced by an external field. Meanwhile the linear coupling between the mechanical resonator and the

We numerically describe the ionization process induced by linearly and circularly polarized extreme ultraviolet (XUV) attosecond laser pulses on an aligned atomic target, specifically the excited state Ne*(1s 22s 22p 5[]3s[]). We compute the excited atomic state by applying the time-dependent restricted-active-space self-consistent field method to fully account for the electronic correlation. We find

The generalized oscillator strengths (GOSs) of the valence-shell excitations of CH3Cl have been determined at an incident electron energy of 1500eV and an energy resolution of about 70 meV. The momentum transfer dependence behaviors of the GOSs of the valence-shell excitations have been carefully analyzed, and the A band shows a strong dipole-forbidden characteristic. By extrapolating the GOSs to the

The photon-spin-dependent (PS) contribution to the ordinary Faraday effect—optical rotation in an external magnetic field is well known. This contribution is proportional to factor where is the photon spin. Recently a -odd Faraday effect—optical rotation in an external electric field —was discussed as a promising tool for observation of the electron electric dipole moment in the intra-cavity absorption

An effective semi-classical method is introduced for controlling the high-order harmonic generation process and extending the cutoff frequency. This method is capable of defining the proper specification of the driving laser for maximizing the cutoff frequency. This method is evaluated by examining the high harmonic spectrum from the hydrogen atom and the fluorine (F2)molecule irradiated by single-

This paper investigates the generation of quantum entanglement by means of conditional stimulated Raman adiabatic passage (STIRAP) based on Rydberg blockade. The paper compares the entanglement fidelities in three-level and four-level schemes and analyzes the adiabatic conditions in both cases. In particular, Green–Horne–Zeilinger states can be deterministically generated in an atomic ensemble interacting

Discrete modulation can make up for the shortage of transmission distance in measurement-device-independent continuous-variable quantum key distribution (MDI-CVQKD), providing a unique advantage against all side-channel attacks but also creating a challenge for further performance improvement. Here we suggest a quantum catalysis (QC) approach for enhancing the performance of the discrete-modulated

We report experimental and theoretical results of two symmetrical signals of degenerate four-wave mixing generated in rubidium vapor. Both nonlinear signals are induced by two almost copropagating laser beams, with and wave-vectors, and detected simultaneously in the and directions. In each direction, we observe a single peak when the two beams are tuned on the closed transition 85Rb 5S 1/2(F = 3)

A target whispering-gallery-mode microresonator (WGMM) directly coupled to a waveguide with an auxiliary side-coupled WGMM is proposed to deterministically extract both the resonant and non-resonant single incident photons from a waveguide. Based on the single-photon Raman interaction (SPRINT) between an Λ-type three-level atom and the target WGMM, a full quantum theory in real space is adopted to

A quantum electrodynamical theory for single-photon diffraction of light from a mesoscopic hole in a quantum well (QW) screen with (Schrdinger) electron dynamics is established. Photon wave mechanics (PWM) is used to extend and bridge the gap between hitherto used semiclassical and quantum optical theoretical approaches for analyses of diffraction of light. An essentially complete calculation is carried

We study the phase separation configurations and rotational properties of a mixture of two interacting charged Bose–Einstein condensates subjected to a magnetic field trapped in disc and Corbino geometries. We calculate the ground state energies of the azimuthal and radial phase separation configurations using the Gross–Pitaevskii and Thomas–Fermi approximations. We show that the results for the experimentally

Inelastic fine rotational cross-sections of the magnesium monohydroxide (MgOH) molecule by collision with helium (He) atoms are investigated. We illustrate the two-dimensional potential energy surface (2D-PES) for the MgOH–He interacting system. The ab initio 2D-PES is computed using the restricted coupled cluster approach with single, double, and perturbative triple excitation connected to an augmented-correlation

The K-shell ionization cross sections of titanium and copper atoms were determined by analyzing the spectra of characteristic X-ray radiation generated by an electron beam with energies of 1 and 2 GeV in metal foils. New data obtained for these energies demonstrate the influence of the density effect on the ionization cross sections values. The results were compared with previous experimental data

Rydberg levels in atomic calcium are of interest due to their use in highly isotope selective multiple-step resonance ionisation spectrometry, and also for nuclear physics investigations, but gaps remain in the data for higher lying levels in calcium isotopes other than . We report novel isotope shift data on four isotopes of calcium (, , , ), relative to the majority abundance isotope , in six Rydberg

The multifrequency resonance has been widely explored in the context of single-particle models, of which the modulating Rabi model has been the most widely investigated. It has been found that with diagonal periodic modulation, steady dynamics can be realized in some well-defined discrete frequencies. These frequencies are independent of off-diagonal couplings. In this work, we generalize this physics

Using electron and ion spectroscopy, we studied the electron and nuclear dynamics in ∼50000-atom large krypton clusters, following excitation with an intense hard x-ray pulse. Beyond the single pulse experiment, we also present the results of a time-resolved, x-ray pump–near-infrared probe measurement that allows one to learn about the time evolution of the system. After core ionization of the atoms

Analytical expressions for integrals involving momentum density have been developed, and an algorithm for the efficient computation of Compton profiles (CPs) based in those equations is reported. The performance of the algorithm is tested by computing the CPs of atoms from helium to xenon for a wide range of incident photon energies. Calculations have been made at Hartree–Fock level (HF), using three

The binding energies of antihydrogen atoms formed when antiprotons are mixed with positron plasmas having densities ranging from 1013–1015m−3, and at temperatures of 5–30K, have been investigated using simulations. Major changes in the distribution of binding energies are observed, with more strongly bound states evident at the higher densities, and at lower temperatures. For deeper binding, the distribution

We study the frustrated tunneling ionization (FTI) in counter-rotating and co-rotating circularly polarized two-color (CPTC) laser fields using a classical electron ensemble method. We find that the FTI probability depends sensitively on the relative helicity and the field amplitude ratio of the two-color laser fields. The FTI probability in the counter-rotating CPTC laser fields is three orders higher

Slow light propagation is an important phenomenon in quantum optics. Here, we theoretically study the properties of slow light in a simple optomechanical system considering an effect of non-rotating wave approximation (NRWA) that was ignored in previous related works. With the NRWA effect, the ultraslow light can be easily achieved at the window of optomechanically induced transparency, especially

We study the excitation redistribution from cesium 7P1/2 or 7P3/2 to neighboring energy levels by black body radiation (BBR) and inter atomic collisions using pump-probe spectroscopy inside a vapor cell. At low vapor densities we measure redistribution of the initial, velocity-selected, atomic excitation by BBR. This redistribution preserves the selected atomic velocities allowing us to perform high

Endofullerene photoionization of open-shell N@C60 is investigated using a coupled-channel, correlated R-matrix approach with additional modifications for a finite spherical-shell fullerene potential. Particular focus is on the initial-state dependence of the photoionization cross section. Comparisons show significant differences between the 1s 22s 22p 3(4S) initial state and the metastable 2D and 2P

We demonstrate how strong-field multiphoton transitions between dynamically shifted atomic levels can be traced in the energy spectra of emitted photoelectrons. Applying an ultrafast and intense laser pulse, two-photon Rabi oscillations are induced between two bound states of an atom. A third photon from the same pulse directly ionizes the atom, thus the emitted photoelectrons coherently probe the

We study the Bloch oscillation (BO) dynamics of spin–orbit coupled cold atoms in a one-dimensional Su–Schrieffer–Heeger optical lattice. The Hamiltonian of our system can be mapped into a tilted SSH ladder pierced by an effective magnetic flux. Based on the calculation of Wannier–Stark states, we investigate dynamical properties of BOs with the chiral character of spin-momentum locking. Importantly

The photodouble ionization of water at about 32eV excess energy has been investigated both experimentally and theoretically. In an energy and angular resolved photoelectron–photoelectron coincidence experiment, the two photoelectrons in unequal energy sharing (25 and 7eV) condition, have been detected in a plane perpendicular to the propagation direction of the linearly polarized radiation. The measured

Optical isolation of the clockwise or the counter-clockwise circular polarization of spectral lines was applied to emission of sputtered tungsten atoms. As a result one measures the weak magnetic field at plasma-surface interface resulting in splitting of spectral lines (W I at 4008.751 and 4982.593 ) being negligibly small with respect to the Doppler broadening. One relies only on the phase rotation

The GeSe and SnSe have great potential in nuclear detector devices. Under irradiation, the formation and migration of point defects may affect their properties and performance significantly. In this study, a comparative study of vacancy formation and migration in GeSe and SnSe has been carried out by a first-principles method. It is shown that in both compounds the cation vacancies are generally much

We present a high-flux source of cold ytterbium atoms that is robust, lightweight and low-maintenance. Our apparatus delivers 1 109 atoms s−1 into a 3D magneto-optical trap without requiring water cooling or high current power supplies. We achieve this by employing a Zeeman slower and a 2D magneto-optical trap fully based on permanent magnets in Halbach configurations. This strategy minimizes mechanical

The electrical strength of a molecule is a measure of its ability to act as an insulator and to absorb electrons. SF6 is a high electric strength gas. This work tries to explain why molecules like SF6 have a high electrical strength from the perspective of electron molecule scattering. The presence of a very low energy (<<1 eV) totally symmetric state in form of a very low-lying resonance, virtual

We present a theoretical study of the polarization-averaged molecular-frame photoelectron angular distributions (PA-MFPADs) emitted from the 1s orbital of oxygen atoms of dissociating dicationic carbon monoxide CO2+. Due to the polarization average, the contribution of the direct wave of the photoelectron, which represents the largest contribution to the MFPADs, is removed, so that the PA-MFPADs clearly

A recent study (2020 Nat. Commun. 11 2334) has found that transitions between multiply-excited configurations in open 4d-subshell tin ions are the dominant contributors to intense EUV emission from dense, Nd:YAG-driven (laser wavelength λ = 1.064μm) tin plasmas. In the present study, we employ the Los Alamos Atomic code to investigate the spectral contribution from these transitions under industrially-relevant