We report a joint theoretical and experimental investigation on low-energy electron scattering by dimethyl and diethyl ethers. The experimental elastic differential cross sections were measured at impact energies from 1 eV up to 30 eV and scattering angle range of 10° to 130°. Theoretical elastic differential, integral and momentum-transfer cross sections are calculated at impact energies up to 30

The Breit correction, the finite-light-speed correction for the Coulomb interaction of the electron–electron interaction in ##IMG## [http://ej.iop.org/images/0953-4075/53/21/215002/babaca6ieqn1.gif] {$O\left(1/{c}^{2}\right)$} , is introduced to density functional theory (DFT) based on the non-relativistic reduction with the local density approximation. Using this newly developed relativistic DFT,

In previous papers we have proposed a method for the ab initio calculation of fully differential cross-sections for electron scattering in liquids and applied it to liquid argon, xenon and krypton. In this paper, we extend the procedure to the consideration of positron scattering in liquid helium, which is complicated by the annihilation process as well as the fact that the electron definition for

Absolute intensity calibrated extreme ultraviolet spectra radiated by highly charged holmium (Ho) ions from 1 μ m Nd:YAG laser generated plasmas in the 1–8 nm wavelength spectral range were measured and investigated. The spectral features show a broad structured continuum-like emission band, most prominent in the wavelength range 6–8 nm, which accounts for more than half of the emitted power. Assuming

In this work, we consider the generalized cubic–quintic dissipative Gross–Pitaevskii equation, which governs the dynamics of matter wave solitons in Bose–Einstein condensates with two- and three-body interatomic interactions in a spatiotemporal-dependent dissipative potential consisting of parabolic, linear, and complex terms. By using the ansatz method, the modulational instability and gray, kink

We discuss the use of a region of uniform and constant magnetic field in order to implement a two-state atomic polarizer for an H(2S) beam. We have observed that a device with such field configuration is capable of achieving an efficient polarization for a wide range of magnetic field intensities and atomic velocities. In addition, we establish a criterion that must be met to confirm a successful polarization

Photoelectron angular distributions for randomly oriented atoms and molecules are characterized by the linear and circular dichroic parameters β and b 1 , respectively. In the region where the photoelectron kinetic energy is several 100 eV, the values of b 1 and β are expected to be constants. In this study, we show that β for all hydrogen atom orbitals other than s orbitals approach values between

We show that it is possible to get gain without inversion at high frequency in a three-level ladder type scheme driven by a single driving laser. The transition from the ground state to first excited state is driven by a low-frequency resonant laser field. The next excited state lies far above the first one; therefore its resonant frequency can be much higher than that of the lower transition, and

First evaluations of the blackbody-radiation (BBR)-induced shift and broadening of highly excited Rydberg states were based on the account of only the first term of the expansion for the Planck’s distribution in powers of the ratio of the BBR-photon energy to the environmental thermal energy. The corresponding asymptotic expression for the shift is proportional to a sum rule for the oscillator strengths

We investigate nonlinear effects on the dynamics of entanglement and other quantum observables in a system of two harmonic modes coupled through angular momentum. The nonlinearity arises from a Kerr-type anharmonic term in each mode. The emergence and evolution of entanglement, non-Gaussianity, photon number, photon antibunching and squeezing are examined for different initial coherent product states

We discuss the non-dipole effect in high-order harmonic generation from atoms driving by a linearly polarized vortex beam. Different from the selection rule under the dipole approximation, where only odd high harmonics are allowed, both even and odd harmonics are generated in the vortex beam. Moreover, the polarization states of the harmonics are modulated. Elliptically polarized high harmonics can

There was a long-standing postulation that the precision of weak-value based metrology using post-selection and spectral analysis is limited by the resolution of spectrometer. Current proposals releasing this limitation require either initially Gaussian spectrum or giving up the weak value amplification approximation, both of which make extra restrictions and increase the difficulty of implementation

We have determined absolute apparent excitation cross sections for photoemission in the 300–1050 nm spectral region resulting from collisions of I 2 with electrons of 4.8–100 eV translational energy. Experiments were done in single collision conditions and emission is observed from I 2 , I 2 + , I and I + . All the emission features appear to turn on at the energy thresholds for formation of the respective

We propose a ground state cooling scheme for an optomechanical resonator based on the system of a V-type three-level QD ensemble trapped in a two-mode cavity. The two-mode cavity was pumped by two different deriving fields. We studied the optomechanical cooling under the highly unresolved-sideband and beyond Lamb-Dicke regime (coupling strength between the cavity field and the phonon field not far

The generation of charge currents and hence induced magnetic field in a spherically bound hydrogen atom by an ultrafast right circularly polarized laser pulse has been studied. The atom is assumed to be under the effect of a Hulthén plus a ring-shaped potential. The simultaneous effect of pulse parameters such as E l 0 , t p and ω 0 , the cavity radius, r 0 , and parameters related to the non-central

The detailed mean-field (MF) treatment of the Bose polaron problem in two and three dimensions is presented. Particularly, assuming that impurity is immersed in the dilute Bose gas and interacts with bosons via the hard-sphere two-body potential, we calculate the low-momentum parameters of its spectrum, namely, the binding energy and the effective mass. The limits of applicability of the MF approach

The realization of electron vortex (EV) beams in the past decade has led to numerous proposed applications in fields from electron microscopy to control and manipulation of individual molecules. Yet despite the many unique characteristics and promising advantages of EV beams, such as transverse momentum and quantized orbital angular momentum, there remains a limited understanding of their fundamental

We study a cascaded system of two subsystems repeatedly interacting with a bath prepared in various non-thermal states. Effects of different types of bath coherence on dynamics of the system heat flux are explored. For a single-qubit bath with the displacement coherence, heat flux of each subsystem is divided into dissipative and coherent parts. In the stationary regime, the dissipative heat fluxes

We present an absolute energy measurement of the K β 1,3 (KM 2,3 ) emission spectrum of scandium ( Z = 21) accurate to 2.1 parts per million (ppm). The previous experimental uncertainty was estimated as 105 ppm, or 0.47 eV, therefore we improve the accuracy of this measurement by a factor of 50 for use in any x-ray standards. There is a long-standing discrepancy between the most recent experimental

We theoretically investigate two-time intensity–intensity correlation spectroscopy in three-level atoms, a spectroscopic method that allows for direct detection of energy level structures and resonances in complex molecules. We show that in three-level Λ or V -systems, a richer spectroscopic signature is obtained when the applied fields are detuned from the transitions to values other than the typical

Vibronic coupling effects usually manifest themselves in molecules and crystals rather than in unbound atoms. We theoretically demonstrate the existence of vibronic states in a moving two-level atom exposed to a strong electromagnetic (EM) wave. In this case, the Rabi oscillations of the electron density give rise to periodic displacements of the atomic nucleus with the Rabi frequency. The periodic

We consider the topological defects and spin structures of spin-1 Bose–Einstein condensates with spin–orbit coupling (SOC) and dipole–dipole interaction (DDI) in a rotating harmonic plus quartic trap. The combined effects of SOC, DDI and rotation on the ground-state phases of the system are analyzed. Our results show that for fixed rotation frequency structural phase transitions can be achieved by

We use the Baranger model to compute collisional broadening and shift rates for the D 1 and D 2 spectral lines of M + Ng, where M = K, Rb, Cs and Ng = He, Ne, Ar. Scattering matrix elements are calculated using the channel packet method, and non-adiabatic wavepacket dynamics are determined using the split-operator method together with a unitary transformation between adiabatic and diabatic representations

Calculations of the photoionization cross sections of the ground states of the superheavy atoms No (Z = 102), Cn (Z = 112) and Og (Z = 118) have been performed using fully relativistic methodologies. The photoionization cross sections are dominated by interchannel coupling, in all cases, over a broad energy range including both outer and inner shells.

Michel Barat passed away in November 2018 at the age of 80 after a rich career in atomic and molecular collisions. He had participated actively in formalizing the electron promotion model, contribuing to low energy reactive collisions at the frontier of chemistry. He investigated electron capture mechanisms by highly charged ions (HCI), switched to collision induced cluster dissociation and finally

We investigate the performance of a three-qubits quantum thermal transistor using coarse-graining, global, and local master equations, respectively. Special attention is paid to the validity of the three methods in different internal coupling strengths. The effects of system and bath parameters on the amplification effect are studied. It is found that small middle qubit frequency, weak internal coupling

We investigate theoretically the formation of ultracold ground-state CsYb molecules on the lowest vibrational level via the Feshbach-optimized photoassociation process. Three s-wave Feshbach resonances of CsYb are found. The probability density of the scattering state in the short-range internuclear distance is significantly enhanced near the resonance positions. The population transfer efficiency

The splitting of magnetic resonance induced by a frequency modulated linearly polarized light field is presented for Hanle experimental configuration. The experiment is carried out with thermal Rubidium atoms in an anti-relaxation coated glass cell. The observed splitting corresponds to steady-state behaviour of the system over an integrated time scale that is longer than the modulation frequency.

We present the first measurements of photoelectron spectra of atomic clusters embedded in superfluid helium (He) nanodroplets. Owing to the large absorption cross section of xenon (Xe) around 100 eV photon energy (4d inner-shell ionization), direct dopant photoionization exceeds charge transfer ionization via the ionized He droplets. Despite the predominant creation of Xe 2+ and Xe 3+ by subsequent

We theoretically investigate the generation of higher harmonics and the construction of a single attosecond pulse (ASP) by means of two oppositely polarized sinc-shaped driver pulses. In comparison to a few-cycle Gaussian pulse of the same energy, here we observe a significant broadening in the bandwidth of the XUV/soft x-ray supercontinuum spectrum in the synthesized pulse. Furthermore, we observe

We report on a global crossover saturated-absorption spectroscopy (SAS) of Cs D 2 transition using a dual-frequency laser field with a frequency difference of less than the Doppler width. With two pairs of dual-frequency laser beams counter-propagating through the vapor cell, the line shape and non-linear features observed in the transmission spectra of the probe beam change with the frequency difference

Neutron-impact single and double ionization cross sections of the He atom are calculated near the neutron-alpha particle collision resonance. Calculations using the time-dependent close-coupling method for total and differential cross sections are made at 8 incident neutron energies ranging from 250 to 2000 keV. At the resonance energy peak the double ionization cross sections unexpectedly become larger

We propose and demonstrate numerically, through time-domain simulations of Maxwell’s equations, a method to generate an oscillatory radiation torque of pN ⋅ μ m strength and sub-picosecond period of oscillation. The approach is based on the change of light’s instantaneous angular momentum as it resonantly excites a micro-cylindrical rod possessing an azimuthally varying continuous refractive index

We propose a scheme that a dynamically evolving atom-molecule condensate maps onto an SU(1, 1) interferometer, which includes a nonlinear medium (nonlinear phase encoding). We give an analytical result of the phase uncertainty from the error propagation by measuring the particle number at the output and demonstrate the optimal quantum metrology, which is obtained with a time-reversal protocol. We show

We report on elastic electron scattering cross sections from Ca and Mg confined by C 60 and C 20 using the optical potential method. We demonstrate the diffuse effect caused by a fullerene cage upon the elastic electron scattering process by employing a commonly used square-well potential and the recently ab initio calculated continuousness electrostatic potential. For Ca@C 60 , we found that the differential

The independence between few-body scales beyond the van der Waals universality is demonstrated for the extreme mass-imbalanced case of a specific many-boson system. This finding generalizes the scaling properties of universal tetramers to a broader class of heterogeneous few-boson systems. We assume two heavy atoms interacting with ( N − 2)-lighter ones at the unitary limit, using a particular case

In this paper we consider a scheme for cryptographic key distribution based on a variation of continuous variable quantum key distribution called central broadcast. In the continuous variable central broadcast scheme, security arises from discord present in the Hanbury Brown and Twiss effect from a thermal source. The benefit of this scheme is that it expands the range of frequencies into the microwave

We theoretically study the collective single excitation dynamics in a chiral-coupled atomic chain with nonreciprocal decay channels. The collective radiation in this one-dimensional (1D) nanophotonics system results from the resonant dipole–dipole interactions in 1D reservoirs, which allow infinite-range couplings between atoms. When a single photon interacts with part of the atomic chain from a side

We model the ( v ′ = 1, v ″ = 0) band of the Birge–Hopfield I band system of molecular nitrogen, N 2 , i.e. ##IMG## [http://ej.iop.org/images/0953-4075/53/19/195204/baba77cieqn1.gif] {${b}^{1}{{\Pi}}_{u}\left({v}^{\prime }=1\right)-{X}^{1}{{\Sigma}}_{g}^{+}\left({v}^{\prime \prime }=0\right)$} , emitted by nonthermal gas discharges in low pressure air. In particular, we calculate the rate of electron

Laser-assisted electron scattering is often described using the electric dipole approximation for the interaction between the electron and the assisting electromagnetic field. Within the dipole approximation, theory predicts a vanishing scattering cross section for processes involving exchange of photons in critical geometries, where the electron momentum transfer vector is perpendicular to the linear

The effect of inner-shell photodetachment channels on outer-shell photodetachment is investigated using the R -matrix method. The simplest multishell closed-shell negative ion, Li − , is examined near the 1 s detachment threshold and the results show that the interchannel coupling significantly alters the shapes and magnitudes of the valence photodetachment cross sections in this energy region.

We theoretically investigate Bloch oscillations in a one-dimensional Bose–Hubbard chain, with single-particle losses from the odd lattice sites described by a Lindblad equation. For a single particle the time evolution of the state is completely determined by a non-Hermitian effective Hamiltonian. We analyse the spectral properties of this Hamiltonian for an infinite lattice and link features of the

By employing the recently developed relativistic normal coupled-cluster theory, we obtained the electric dipole moment (EDM) of 225 Ra due to nuclear Schiff moment (NSM) and tensor–pseudotensor (T–PT) electron–nucleus (e–N) interaction as −6.3(5) × 10 −17 S |e| cm/(|e| fm 3 ) and −13(1) × 10 −20 C T ⟨ σ N ⟩ |e| cm, respectively, for the NSM S , T–PT coupling coefficient C T and nuclear Pauli spinor

The development of attosecond pump–probe experiments at high repetition rate requires the development of novel attosecond sources maintaining a sufficient number of photons per pulse. We use 7 fs, 800 nm pulses from a non-collinear optical parametric chirped pulse amplification laser system to generate few-pulse attosecond pulse trains (APTs) with a flux of >10 6 photons per shot in the extreme ultraviolet

A two-dimensional hybrid cavity optomechanical array formed by an optomechanical cavity embedded with a two-level atom in each site is introduced to discuss the superfluid–Mott insulator quantum phase transition of light. On account of the optomechanical coupling effects stemmed from the coupled movable oscillator, the energy spectrum of the system changes, and an effective on-site repulsive interaction

This review summarizes the path-breaking contributions of Philip George Burke (1932–2019) to atomic, molecular, and optical physics, in particular the computational treatment of electron and photon collisions with atoms, ions, and molecules.

Resonance energies and widths of eight long-lived metastable electronic states of the CO − anion are obtained using the R -matrix method as a function of bond distance. High-level ab initio scattering calculations are performed for a large number (above 150) of fixed-nuclear geometries using the large cc-pV6Z Gaussian basis set and a close-coupling model involving 27 low-lying target states. Potential

We review the recent experimental and theoretical progress in K -shell detachment studies of atomic anions. On the experimental side, this field has largely benefitted from technical advances at 3rd generation synchrotron radiation sources. For multiple detachment of C − , O − , and F − ions, recent results were obtained at the photon-ion merged-beams setup PIPE which is a permanent end station at

We investigate the high-harmonic generation from CO molecules subjected to intense few-cycle laser fields by numerically solving the time-dependent Hartree–Fock equations. A dynamic minimum due to the interference of the HOMO and HOMO-2 orbitals is observed in the harmonic spectrum and further studies reveal that the HOMO-1 orbital plays an indispensable role in the formation of the minimum. Because

We study the dynamics of binary Bose–Einstein condensates made of ultracold and dilute alkali-metal atoms in a quasi-one-dimensional setting. Numerically solving the two coupled Gross–Pitaevskii equations which accurately describe the system dynamics, we demonstrate that the spin transport can be controlled by suitably quenching spin–orbit and Rabi coupling strengths. Moreover, we predict a variety

We demonstrate the enhancement of harmonics in the vicinity of 32 nm while generating them in the Mo laser-produced plasma. The enhanced harmonics centered at around the 25th harmonic of 806 nm radiation were analyzed by different means (delay between heating and driving pulses, dependences of harmonic yield on the driving and heating pulse intensities and durations, different regimes of plasma formation

The interference fringes of above-threshold ionization (ATI) spectrum from atoms or molecules have been extensively studied. In this paper, we investigate the ATI of the polyatomic molecule SF 6 in IR + XUV two-color laser fields, and find that some interference fringes on the spectrum are from the molecular structure, which is independent of the parameters of the laser field. Based on the frequency-domain

Triplet ( S = 1) He Rydberg atoms in supersonic beams with an initial velocity of 350 m s −1 have been decelerated to zero velocity and loaded into an off-axis electric trap in the presence and absence of magnetic fields. Comparing the deceleration efficiencies and the radiative decay of the population of trapped He Rydberg atoms to the (1s) 1 (2s) 1 3 S 1 metastable level in the two sets of deceleration

We have developed a semiclassical approach to the description of resonant dissociative excitation of a molecular ion induced by collisions with plasma free electrons and accompanied by the non-adiabatic transitions between its different electronic terms. It is based on the quasistatic treatment of nuclear particles relative motion in a molecular ion combined with the approximation of a quasicontinuum

The angular distribution of O 1s photoelectrons emitted from uniaxially oriented methanol is studied experimentally and theoretically. We employed circularly polarized photons of an energy of hν = 550 eV for our investigations. We measured the three-dimensional photoelectron angular distributions of methanol, with the CH 3 –OH axis oriented in the polarization plane, by means of cold target recoil

Two characterisations of the Cu K β 1,3 spectrum are developed, which are robust and transferable to other experimental x-ray geometries. By observing and considering the significant contribution of radiative Auger emission to the K β profile, we obtain an improved and more robust characterisation. The contribution of the KM 2,3 M 4,5 and KM 2,3 N 1 radiative Auger satellites to the K β 1,3 spectrum

The electric field of attosecond laser pulses can be retrieved from laser-dressed photoionisation measurements, where electron wavepackets that result from single-photon ionisation by the attosecond pulse in the presence of a dressing field are produced. In case of fluctuating dressing laser and/or attosecond pulses, e.g. due to pulse-to-pulse fluctuations of the carrier envelope phase of the infrared

Emission spectra from multiply-charged Sn 5+ –Sn 10+ ions are recorded from an electron beam ion trap (EBIT) and from laser-produced plasma (LPP) in the extreme ultraviolet range relevant for nanolithographic applications. Features in the wavelength regime between 12.6 and 20.8 nm are studied. Using the Cowan code, emission line features of the charge-state-resolved Sn ion spectra obtained from the

We investigate the ratio R of the intensity of the blended lines 3d 3/2,5/2 → 2p 3/2 over that of the resonance line 3d 3/2 → 2p 1/2 emitted by boron-like Ar 13+ ions after impact excitation by an electron beam. We calculate R as a function of the electron density n e in the range 10 9 –10 13 cm −3 , for incident-electron energies from 0.46 to 5.5 keV. The calculations take into account the anisotropy

In this paper, we review the development and application of coherent short wavelength light sources implemented using the high harmonic generation (HHG) process. The physics underlying HHG brought quantum physics into the domain of attosecond time-scales for the first time. The observation and manipulation of electron dynamics on such short time-scales—a capability not conceived—of just a few decades