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Photoelectron holographic interferometry to probe the longitudinal momentum offset at the tunnel exitApr 21 2019Laser-induced electron tunneling underlies numerous emerging spectroscopic techniques to probe attosecond electron dynamics in atoms and molecules. The improvement of those techniques requires an accurate knowledge of the exit momentum for the tunneling ... More

Gravity surveys using a mobile atom interferometerApr 19 2019Mobile gravimetry is important in metrology, navigation, geodesy, and geophysics. Atomic gravimeters could be among the most accurate mobile gravimeters, but are currently constrained by being complex and fragile. Here, we demonstrate a mobile atomic ... More

Efficient $2^3S$ positronium production by stimulated decay from the $3^3P$ levelApr 18 2019We investigate experimentally the possibility of enhancing the production of $2^3S$ positronium atoms by driving the $1^3S$-$3^3P$ and $3^3P$-$2^3S$ transitions, overcoming the natural branching ratio limitation of spontaneous decay from $3^3P$ to $2^3S$. ... More

Microwave-to-optical conversion via four-wave-mixing in a cold ytterbium ensembleApr 18 2019Interfacing superconducting qubits with optical photons requires noise-free microwave-to-optical transducers, a technology currently not realized at the single-photon level. We propose to use four-wave-mixing in an ensemble of cold ytterbium (Yb) atoms ... More

Decoherence of dipolar spin ensembles in diamondApr 18 2019We present a combined theoretical and experimental study of solid-state spin decoherence in an electronic spin bath, focusing specifically on ensembles of nitrogen vacancy (NV) color centers in diamond and the associated substitutional nitrogen spin bath. ... More

Transient dynamics of nonlinear magneto-optical rotation in the presence of transverse magnetic fieldApr 18 2019Nonlinear magneto-optical rotation is studied under non-equilibrium conditions. The polarization rotation of linearly polarized light traversing a rubidium vapor cell is observed versus the time-dependent (swept) longitudinal magnetic field in the presence ... More

A density functional method for general excited states in atomsApr 18 2019This chapter presents the development of a density functional theory (DFT)-based method for accurate, reliable treatment of various resonances in atoms. Many of these are known to be notorious for their strong correlation, proximity to more than one thresholds, ... More

Pure Molecular Beam of Water DimerApr 18 2019Spatial separation of water dimer from water monomer and larger water-clusters through the electric deflector is presented. A beam of water dimer with $93~\%$ purity and a rotational temperature of $1.5~$K was obtained. Following strong-field ionization ... More

Pure Molecular Beam of Water DimerApr 18 2019Apr 19 2019Spatial separation of water dimer from water monomer and larger water-clusters through the electric deflector is presented. A beam of water dimer with $93~\%$ purity and a rotational temperature of $1.5~$K was obtained. Following strong-field ionization ... More

Spin image of an atomic vapor cell with a resolution smaller than the diffusion crosstalk free distanceApr 18 2019The diffusion crosstalk free distance is an important parameter for spin images in atomic vapor cells and is also regarded as a limit on the spatial resolution. However, by modulating the pumping light both spatially and temporally using a digital micromirror ... More

Power narrowing: Counteracting Doppler broadening in two-color transitionsApr 17 2019Doppler broadening in thermal ensembles degrades the absorption cross-section and the coherence time of collective excitations. In two photon transitions, it is common to assume that this problem becomes worse with larger wavelength mismatch. Here we ... More

Variation of the transition energies and oscillator strengths for the 3C and 3D lines of the Ne-like ions under plasma environmentApr 17 2019We present the results of a detailed theoretical study which meets the spatial and temporal criteria of the Debye-Hu\"ckel (DH) approximation on the variation of the transition energies as well as the oscillator strengths for the ${2p^53d\ ^1P_1\rightarrow2p^6\ ... More

Dynamical spin-orbit coupling of a quantum gasApr 17 2019We realize the dynamical 1D spin-orbit-coupling (SOC) of a Bose-Einstein condensate confined within an optical cavity. The SOC emerges through spin-correlated momentum impulses delivered to the atoms via Raman transitions. These are effected by classical ... More

Precision spectroscopy of negative-ion resonances in Rydberg moleculesApr 17 2019The level structure of negative-ions near the electron detachment limit dictates the low-energy scattering of an electron with the parent neutral atom. We demonstrate that a single ultracold atom bound inside a Rydberg orbit forming an ultralong-range ... More

Controlling Dipolar Exchange Interactions in a Dense 3D Array of Large Spin FermionsApr 17 2019Dipolar interactions are ubiquitous in nature and rule the behavior of a broad range of systems spanning from energy transfer in biological systems to quantum magnetism. Here, we study magnetization-conserving dipolar induced spin-exchange dynamics in ... More

Highly-polarizable ion in a Paul trapApr 17 2019Usually the influence of the quadratic Stark effect on an ion's trapping potential is minuscule and only needs to be considered in atomic clock experiments. In this work we excite a trapped ion to a Rydberg state with polarizability $\sim$~eight orders ... More

Deep Learning-Assisted Classification of Site-Resolved Quantum Gas Microscope ImagesApr 17 2019We present a novel method for the analysis of quantum gas microscope images, which uses deep learning to improve the fidelity with which lattice sites can be classified as occupied or unoccupied. Our method is especially suited to addressing the case ... More

Correlation enhancement of high-order harmonics generation in XeApr 17 2019We consider the process of high-order harmonics generation (HHG) in the xenon atom enhanced by the inter-shell correlation between the valence 5p and inner 4d shells. We derive the HHG spectrum from a numerical solution of the one-electron time-dependent ... More

Dicarbon formation in collisions of two carbon atomsApr 16 2019Radiative association cross sections and rates are computed, using a quantum approach, for the formation of C$_2$ molecules (dicarbon) during the collision of two ground state C($^3$P) atoms. We find that transitions originating in the C$\;^1\Pi_g$, d$\;^3\Pi_g$, ... More

Fluorescence-lifetime-limited trapping of Rydberg helium atoms on a chipApr 16 2019Metastable (1s)(2s) $^3{\rm S}_1$ helium atoms produced in a supersonic beam were excited to Rydberg-Stark states (with $n$ in the $27-30$ range) in a cryogenic environment and subsequently decelerated by, and trapped above, a surface-electrode decelerator. ... More

Precision measurement of spin-dependent inter-hyperfine scattering lengths in $^{87}$RbApr 16 2019We present precision measurements of the $f=1$ to $f=2$ inter-hyperfine scattering lengths in a single-domain $^{87}$Rb spinor Bose-Einstein condensate. The inter-hyperfine interaction leads to a strong and state-dependent modification of the spin-mixing ... More

Precision measurement of spin-dependent inter-hyperfine scattering lengths in $^{87}$RbApr 16 2019Apr 17 2019We present precision measurements of the $f=1$ to $f=2$ inter-hyperfine scattering lengths in a single-domain $^{87}$Rb spinor Bose-Einstein condensate. The inter-hyperfine interaction leads to a strong and state-dependent modification of the spin-mixing ... More

Comment on "Electron impact excitation and ionization cross section of tungsten ions, W$^{44+}$" by El-Maaref et al. [J. Quant. Spectrosc. Radiat. Transfer 2019, 224:147]Apr 16 2019In a recent paper, El-Maaref et al. [J. Quant. Spectrosc. Radiat. Transfer 2019, 224:147] have reported atomic data for Zn-like W~XLV. Their results are mainly for energy levels, radiative rates, collision strengths ($\Omega$) for electron impact excitation, ... More

Strong-field photoelectron momentum imaging of OCS at finely resolved incident intensitiesApr 16 2019Photoelectron momentum distributions from strong-field ionization of carbonyl sulfide with 800 nm central-wavelength laser pulses at various peak intensities from $4.6$ to $13\times10^{13}$ W/cm$^2$ were recorded and analyzed regarding resonant Rydberg ... More

Precise assignment of excited-state bond length using branching ratio measurements: The B$^2Σ^+$ state of BaH moleculesApr 15 2019Vibrational branching ratios in the B$^2\Sigma^+$ -- X$^2\Sigma^+$ and A$^2\Pi$ -- X$^2\Sigma^+$ optical-cycling transitions of BaH molecules are investigated using spectroscopic measurements and {\it ab initio} calculations. The experimental values are ... More

United test of the equivalence principle at $10^{-10}$ level using mass and internal energy specified atomsApr 15 2019We use both mass and internal energy specified rubidium atoms to jointly test the weak equivalence principle (WEP). We improve the four-wave double-diffraction Raman transition method (FWDR) we proposed before to select atoms with certain mass and angular ... More

Temperature-induced negative differential conductivityApr 14 2019We report on the existence of temperature induced negative differential conductivity (NDC) for electrons in gaseous nitrogen. The important role of superelastic rotational collisional processes in this phenomenon is highlighted. A model cross-section ... More

Towards the theory of Potential Energy Curves for diatomic molecular ions: He$_2^+$ caseApr 14 2019Elements of the general theory of potential curves for diatomic molecules are presented. For the diatomic molecule He$_2^+$ in Born-Oppenheimer (BO) approximation it is presented the approximate analytic expression for the potential energy curves $V(R)$ ... More

Measurement of the radial matrix elements for the $6s ^2S_{1/2} \rightarrow 7p ^2P_J$ transitions in cesiumApr 12 2019We report measurements of the electric dipole matrix elements of the $^{133}$Cs $\ $ $6s\,^2S_{1/2} \rightarrow 7p\,^2P_{1/2}$ and $6s\,^2S_{1/2} \rightarrow 7p\,^2P_{3/2}$ transitions. Each of these determinations is based on direct, precise comparisons ... More

Imaging recoil ions from optical collisions between ultracold, metastable neon isotopesApr 11 2019We present an experimental scheme which combines the well established method of velocity-mapimaging, with a cold trapped metastable neon target. The device is used for obtaining the branching ratios and recoil-ion energy distributions for the penning ... More

Quench induced vortex-bright-soliton formation in binary Bose-Einstein condensatesApr 11 2019We unravel the spontaneous generation of vortex-bright-soliton structures in binary Bose-Einstein condensates confined in a two-dimensional harmonic trap where one of the two species has been segmented into two parts by a potential barrier. To trigger ... More

Highly efficient isotope separation and ion implantation of $^{163}$Ho for the ECHo projectApr 11 2019The effective electron neutrino mass measurement at the ECHo experiment requires high purity $^{163}$Ho, which is ion implanted into detector absorbers. To meet the project specifications in efficiency and purity, the entire process chain of ionization, ... More

Spin-exchange-induced exotic superfluids in a Bose-Fermi spinor mixtureApr 11 2019We consider a mixture of spin-1/2 bosons and fermions, where only the bosons are subjected to the spin-orbit coupling induced by Raman beams. The fermions, although not directly coupled to the Raman lasers, acquire an effective spin-orbit coupling through ... More

Reconstruction of tunnel exit time and exit momentum in strong field ionization, based on phase space methodsApr 10 2019We analyze tunnel ionization of a single atom based on the Wigner function over the classical phase space which inspires improved classical electron trajectories: these start with exit momenta based on the quantum momentum function and correspond very ... More

High-energy bremsstrahlung on atoms in a laser fieldApr 10 2019The impact of a laser field on the process of photon radiation by an ultra-relativistic electron in an atomic field is investigated. The angular distribution and the spectrum of the radiated photon are derived. By means of the quasiclassical approximation, ... More

Three two-component fermions with contact interactions: correct formulation and energy spectrumApr 09 2019Properties of two identical particles of mass $m$ and a distinct particle of mass $m_1$ in the universal low-energy limit of zero-range two-body interaction are studied in different sectors of total angular momentum $L$ and parity $P$. For the unambiguous ... More

Molecular lattice clock with long vibrational coherenceApr 09 2019Atomic lattice clocks have spurred numerous ideas for tests of fundamental physics, detection of general relativistic effects, and studies of interacting many-body systems. On the other hand, molecular structure and dynamics offer rich energy scales that ... More

Beyond Fermi's Golden Rule in Free-Electron Quantum Electrodynamics: Acceleration/Radiation CorrespondenceApr 09 2019In this article, we present a unified reciprocal quantum electrodynamics (QED) formulation of quantum light-matter interaction. For electron-light interactions, we bridge the underlying theories of Photon-Induced Near-field Electron Microscopy (PINEM), ... More

Gas $^3$He NMR Probe for Cryogenic EnvironmentsApr 09 2019Normal NMR probes cannot be used to make high frequency resolution measurements in a cryogenic environment because they lose their frequency resolution when the liquid sample in the probe freezes. A gaseous $^3$He NMR probe, designed and constructed to ... More

Circular holographic ionization-phase meterApr 08 2019We propose an attosecond XUV-pump IR-probe photoionization protocol that employs pairs of counter-rotating consecutive harmonics and angularly resolved photoelectron detection, thereby providing direct measurement of ionization phases. The present method, ... More

Low-Energy Scattering Properties of Ground-State and Excited-State Positronium CollisionsApr 08 2019Low-energy elastic and inelastic scattering in the Ps(1$s$)-Ps(2$s$) channel is treated in a four-body hyperspherical coordinate calculation. Adiabatic potentials are calculated for triplet-triplet, singlet-singlet, and singlet-triplet spin symmetries ... More

Trapped-Ion Quantum Computing: Progress and ChallengesApr 08 2019Trapped ions are among the most promising systems for practical quantum computing (QC). The basic requirements for universal QC have all been demonstrated with ions and quantum algorithms using few-ion-qubit systems have been implemented. We review the ... More

Raman stimulated neutrino pair emissionApr 08 2019A new scheme using macroscopic coherence is proposed from a theoretical point to experimentally determine the neutrino mass matrix, in particular the absolute value of neutrino masses, and the mass type, Majorana or Dirac. The proposed process is a collective, ... More

Fingerprints of slingshot non-sequential double ionization on two-electron probability distributionsApr 06 2019We study double ionization of He driven by a near-single-cycle laser pulse at low intensities at 400 nm. Using a three-dimensional semiclassical model, we identify the pathways that prevail non-sequential double ionization (NSDI). We focus mostly on the ... More

Number-resolved imaging of $^{88}$Sr atoms in a long working distance optical tweezerApr 05 2019Apr 18 2019We demonstrate the number-resolved detection of individual strontium atoms in an optical tweezer. Using a long-working distance low numerical aperture (NA = 0.26) tweezer, we avoid parity projection due to light-assisted collisions, and are able to resolve ... More

Number-resolved imaging of $^{88}$Sr atoms in a long working distance optical tweezerApr 05 2019We demonstrate the number-resolved detection of individual strontium atoms in an optical tweezer. Using a long-working distance low numerical aperture (NA = 0.26) tweezer, we avoid parity projection due to light-assisted collisions, and are able to resolve ... More

Hopf characterization of two-dimensional Floquet topological insulatorsApr 05 2019We present a topological characterization of time-periodically driven two-band models in $2+1$ dimensions as Hopf insulators. The intrinsic periodicity of the Floquet system with respect to both time and the underlying two-dimensional momentum space constitutes ... More

Microscopic characteristics and tomography scheme of the local Chern markerApr 05 2019The concept of the local Chern marker has gained a lot of attention especially in the field of ultracold quantum gases in optical lattices and artificial gauge fields. We investigate in further detail the microscopic real-space characteristics of the ... More

Single-Photon Pulse Induced Transient Entanglement ForceApr 04 2019We show that a single photon pulse (SPP) incident on two interacting two-level atoms induces a transient entanglement force between them. After absorption of a multi-mode Fock state pulse, the time-dependent atomic interaction mediated by the vacuum fluctuations ... More

Bose polarons near quantum criticalityApr 04 2019The emergence of quasiparticles in strongly interacting matter represents one of the cornerstones of modern physics. However, when different phases of matter compete near a quantum critical point, the very existence of quasiparticles comes under question. ... More

Bose polarons near quantum criticalityApr 04 2019Apr 10 2019The emergence of quasiparticles in strongly interacting matter represents one of the cornerstones of modern physics. However, when different phases of matter compete near a quantum critical point, the very existence of quasiparticles comes under question. ... More

High accuracy theoretical investigations of CaF, SrF, and BaF and implications for laser-coolingApr 04 2019The NL-eEDM collaboration is building an experimental setup to search for the permanent electric dipole moment of the electron in a slow beam of cold barium fluoride molecules [Eur. Phys. J. D, 72, 197 (2018)]. Knowledge of molecular properties of BaF ... More

Pressure Shifts in High-Precision Hydrogen Spectroscopy: II. Impact Approximation and Monte-Carlo SimulationsApr 04 2019We investigate collisional shifts of spectral lines involving excited hydrogenic states, where van der Waals coefficients have recently been shown to have large numerical values when expressed in atomic units. Particular emphasis is laid on the recent ... More

Pressure Shifts in High-Precision Hydrogen Spectroscopy: I. Long-Range Atom-Atom and Atom-Molecule InteractionsApr 04 2019We study the theoretical foundations for the pressure shifts in high-precision atomic beam spectrosopy of hydrogen, with a particular emphasis on transitions involving higher excited P states. In particular, the long-range interaction of an excited hydrogen ... More

Interference-assisted detection of dark photon using atomic transitionsApr 03 2019Dark photon is a massive vector particle which couples to the physical photon through the kinetic mixing term. Such particles, if exist, are produced in photon beams and, in particular, in laser radiation. Due to the oscillations between the physical ... More

Comparison of semiclassical and quantum models of a two-level atom-cavity QED system in the strong coupling regimeApr 03 2019Apr 05 2019We present a numerical study comparing semiclassical and quantum models of a damped, strongly interacting cavity QED system composed of a single two-level atom interacting with a single quantized cavity mode driven externally by a tunable monochromatic ... More

Comparison of semiclassical and quantum models of a two-level atom-cavity QED system in the strong coupling regimeApr 03 2019We present a numerical study comparing semiclassical and quantum models of a damped, strongly interacting cavity QED system composed of a single two-level atom interacting with a single quantized cavity mode driven externally by a tunable monochromatic ... More

An optical lattice based method for precise measurements of atomic parity violationApr 03 2019We propose a method for measuring parity violation in neutral atoms. It is an adaptation of a seminal work by Fortson [Phys. Rev. Lett. {\bf 70}, 2383 (1993)], proposing a scheme for a single trapped ion. In our version, a large sample of neutral atoms ... More

Transport of light through a dense ensemble of cold atoms in a static electric fieldApr 03 2019We demonstrate that the transport of coherent quasiresonant light through a dense cloud of immobile two-level atoms subjected to a static external electric field can be described by a simple diffusion process up to atomic number densities of the order ... More

Quantum electrodynamic corrections to the $1s3d$ states of the helium atomApr 03 2019We perform quantum electrodynamic calculations of the ionization energy of the $1s3d$ states of the $^4$He atom, including a complete evaluation of the $m\alpha^6$ correction. We find a large contribution from the nonradiative part of this correction, ... More

Spurious Ferromagnetic Remanence Detected by Hybrid MagnetometerApr 03 2019Nuclear magnetic resonance detection in ultra low field regime enables the measurement of different components of a spurious remanence in the polymeric material constituting the sample container. A differential atomic magnetometer detects simultaneously ... More

Interaction of antiproton with helium based on ab-initio calculationsApr 03 2019We present ionization cross sections for antiproton and helium collisions based on ab-initio time-dependent coupled channel method. In our calculations a finite basis set of regular helium Coulomb wave packets and Slater function were used. The semiclassical ... More

Transporting long-lived quantum spin coherence in a photonic crystal fiberApr 03 2019Confining particles in hollow-core photonic crystal fibers has opened up new prospects to scale up the distance and time over which particles can be made to interact with light. However, maintaining long-lived quantum spin coherence and/or transporting ... More

Ultracold homonuclear and heteronuclear collisions in metastable heliumApr 02 2019Scattering and ionizing cross sections and rates are calculated for ultracold collisions between metastable helium atoms using a fully quantum-mechanical close-coupled formalism. Homonuclear collisions of the bosonic ${}^{4}$He$^{*} +{}^{4}$He$^{*}$ and ... More

The concept of laser-based conversion electron Mössbauer spectroscopy for a precise energy determination of $^{229m}$ThApr 02 2019$^{229}$Th is the only nucleus currently under investigation for the development of a nuclear optical clock (NOC) of ultra-high accuracy. The insufficient knowledge of the first nuclear excitation energy of $^{229}$Th has so far hindered direct nuclear ... More

Quantum Physics Meets Music: A "Real-Time" Guitar Recording Using Rydberg-Atoms and Electromagnetically Induced TransparencyApr 02 2019We demonstrate how Rydberg atoms and the phenomena of electromagnetically induced transparency can be used to aid in the recording of a musical instrument in real time as it is played. Also, by using two different atomic species (cesium and rubidium) ... More

Realization of a high power optical trapping setup free from thermal lensing effectsApr 01 2019Transmission of high power laser beams through partially absorbing materials modifies the light propagation via a thermally-induced effect known as thermal lensing. This may cause changes in the beam waist position and degrade the beam quality. Here we ... More

Are ultracold molecular collisions sticky?Apr 01 2019Understanding and controlling collisions is crucial to the burgeoning field of ultracold molecules. All experiments so far have observed fast loss of molecules from the trap. However, the dominant mechanism for collisional loss is not well understood ... More

Atomic parity violation and the standard modelMar 30 2019A concise review of atomic parity violation with a focus on the measurement and interpretation of parity violation in cesium.

Excitation and charge transfer in low-energy hydrogen atom collisions with neutral carbon and nitrogenMar 30 2019Low-energy inelastic collisions with neutral hydrogen atoms are important processes in stellar atmospheres, and a persistent source of uncertainty in non-LTE modelling of stellar spectra. We calculate and study excitation and charge transfer of C i and ... More

Lasing on a narrow transition in a cold thermal strontium ensembleMar 29 2019Highly stable laser sources based on narrow atomic transitions provide a promising platform for direct generation of stable and accurate optical frequencies. Here we investigate a simple system operating in the high-temperature regime of cold atoms. The ... More

On the possibility of observable signatures of $ μp $ and $ (μ ^4\mathrm{He})^{+} $ lines on the spectra of astrophysical sourcesMar 28 2019We examine the processes of the luminescence in subordinate lines of muonic hydrogen $ \mu p $ and muonic helium ion $ (\mu ^4\mathrm{He})^{+} $ in the presence of background source of X-ray emission. It is supposed that a certain amount of muonic atoms ... More

Attosecond dynamics through a Fano resonance: Monitoring the birth of a photoelectronMar 27 2019Amplitude and phase of wavepackets encode the dynamics of quantum systems. However, the rapidity of electron dynamics on the attosecond timescale has precluded their complete measurement in the time domain. Here, we demonstrate that spectrally-resolved ... More

Relativistic Coupled-Cluster Study of Diatomic Metal-Alkali Molecules for Electron Electric Dipole Moment SearchesMar 27 2019Recent improvements in experimental techniques for preparing ultracold molecules that contain alkali atoms (e.g., Li, Na, and K) have been reported. Based on these advances in ultracold molecules, new searches for the electric dipole moment of the electron ... More

$g$ Factor of Lithiumlike Silicon: New Challenge to Bound-State QEDMar 27 2019The recently established agreement between experiment and theory for the $g$ factors of lithiumlike silicon and calcium ions manifests the most stringent test of the many-electron bound-state quantum electrodynamics (QED) effects in the presence of a ... More

Probing Nonlocal Spatial Correlations in Quantum Gases with Ultra-long-range Rydberg MoleculesMar 27 2019We present photo-excitation of ultra-long-range Rydberg molecules as a probe of spatial correlations in quantum gases. Rydberg molecules can be created with well-defined internuclear spacing, set by the radius of the outer lobe of the Rydberg electron ... More

A Frenet-Serret Interpretation of Particle Dynamics in High-Intensity Laser FieldsMar 27 2019In this paper we discuss the dynamics of charged particles in high-intensity laser fields in the context of the Frenet-Serret formalism, which describes the intrinsic geometry of particle worldlines. We find approximate relations for the Frenet-Serret ... More

Simulations of Majorana spin flips in an antihydrogen trapMar 27 2019The properties of antihydrogen ($\bar{\rm H}$) have, thus far, been probed at magnetic fields of $\sim 1$ T. It may be fruitful to perform some of these measurements at magnetic fields approaching 0 T. In this case, there could occur zeros in the magnitude ... More

Compact Optical Atomic Clock Based on a Two-Photon Transition in RubidiumMar 27 2019Extra-laboratory atomic clocks are necessary for a wide array of applications (e.g. satellite-based navigation and communication). Building upon existing vapor cell and laser technologies, we describe an optical atomic clock, designed around a simple ... More

Non-adiabatic Storage of Short Light Pulses in an Atom-Cavity SystemMar 26 2019We demonstrate the storage of $5$~ns light pulses in an intrinsically fiber-coupled atomic memory. Our storage protocol addresses a regime beyond the conventional adiabatic limit, for which we extract the optimal control laser pulse properties from a ... More

Application of the time-dependent surface flux method to the time-dependent multiconfiguration self-consistent-field methodMar 26 2019We present a numerical implementation of the time-dependent surface flux (tSURFF) method [New J. Phys. 14, 013021 (2012)], an efficient computational scheme to extract photoelectron energy spectra, to the time-dependent multiconfiguration self-consistent-field ... More

Application of the time-dependent surface flux method to the time-dependent multiconfiguration self-consistent-field methodMar 26 2019Mar 28 2019We present a numerical implementation of the time-dependent surface flux (tSURFF) method [New J. Phys. 14, 013021 (2012)], an efficient computational scheme to extract photoelectron energy spectra, to the time-dependent multiconfiguration self-consistent-field ... More

Detecting and Receiving Phase Modulated Signals with a Rydberg Atom-Based MixerMar 26 2019Recently, we introduced a Rydberg-atom based mixer capable of detecting and measuring the phase of a radio-frequency field through the electromagnetically induced transparency (EIT) and Autler-Townes (AT) effect. The ability to measure phase with this ... More

First principle simulation of ultra-cold ion crystals in a Penning trap with Doppler cooling and a rotating wall potentialMar 25 2019A direct numerical simulation of many interacting ions in a Penning trap with a rotating wall is presented. The ion dynamics is modelled classically. Both axial and planar Doppler laser cooling are modeled using stochastic momentum impulses based on two-level ... More

Superradiant laser with metastable calcium atomsMar 25 2019Cold samples of calcium atoms are prepared in the metastable $^{3}$P$_{1}$ state inside an optical cavity resonant with the narrow band (375 Hz) $^{1}$S$_{0} \rightarrow ^{3}$P$_{1}$ intercombination line at 657 nm. We observe superradiant emission through ... More

Detection of radiation torque exerted on an alkali-metal vapor cellMar 25 2019We have developed a torsion balance to detect the rotation of a cell containing spin-polarized gaseous atoms to study angular momentum transfer from gaseous atoms to solid. A cesium vapor cell was hung from a thin wire in a vacuum chamber, and irradiated ... More

Feedback-Induced Quantum Phase Transitions Using Weak MeasurementsMar 25 2019We show that applying feedback and weak measurements to a quantum system induces phase transitions beyond the dissipative ones. Feedback enables controlling essentially quantum properties of the transition, i.e., its critical exponent, as it is driven ... More

Concept study and preliminary design of a cold atom interferometer for space gravity gradiometryMar 23 2019We study a space-based gravity gradiometer based on cold atom interferometry and its potential for the Earth's gravitational field mapping. The instrument architecture has been proposed in [Carraz et al., Microgravity Science and Technology 26, 139 (2014)] ... More

Isotope shifts of the $1s^22s2p(J)$ -$1s^22s^2$ transition energies in Be-like thorium and uraniumMar 23 2019Precise calculations of the isotope shifts in berylliumlike thorium and uranium ions are presented. The main contributions to the field and mass shifts are calculated within the framework of the Dirac-Coulomb-Breit Hamiltonian employing the configuration-interaction ... More

QED theory of the specific mass shift in atomsMar 22 2019The quantum electrodynamics formalism to treat the interelectronic-interaction correction of first order in $1/Z$ to the two-electron part of the nuclear recoil effect on binding energies in atoms and ions is developed. The nonperturbative in $\alpha ... More

Weak Electric-Field Detection with Sub-1 Hz Resolution at Radio Frequencies Using A Rydberg Atom-Based MixerMar 22 2019Rydberg atoms have been used for measuring radio-frequency (RF) electric (E)-fields due to their strong dipole moments over the frequency range of 500 MHz-1 THz. For this, electromagnetically induced transparency (EIT) within the Autler-Townes (AT) regime ... More

ZERODUR based optical systems for quantum gas experiments in spaceMar 22 2019Apr 01 2019Numerous quantum technologies make use of a microgravity environment e.g. in space. Operating in this extreme environment makes high demands on the experiment and especially the laser system regarding miniaturization and power consumption as well as mechanical ... More

ZERODUR$^©$ based optical systems for quantum gas experiments in spaceMar 22 2019Numerous quantum technologies make use of a microgravity environment e.g. in space. Operating in this extreme environment makes high demands on the experiment and especially the laser system regarding miniaturization and power consumption as well as mechanical ... More

ZAIGA: Zhaoshan Long-baseline Atom Interferometer Gravitation AntennaMar 22 2019Mar 26 2019The Zhaoshan long-baseline Atom Interferometer Gravitation Antenna (ZAIGA) is a new type of underground laser-linked interferometer facility, and is currently under construction. It is in the 200-meter-on-average underground of a mountain named Zhaoshan ... More

ZAIGA: Zhaoshan Long-baseline Atom Interferometer Gravitation AntennaMar 22 2019Apr 16 2019The Zhaoshan long-baseline Atom Interferometer Gravitation Antenna (ZAIGA) is a new type of underground laser-linked interferometer facility, and is currently under construction. It is in the 200-meter-on-average underground of a mountain named Zhaoshan ... More

ZAIGA: Zhaoshan Long-baseline Atom Interferometer Gravitation AntennaMar 22 2019The Zhaoshan long-baseline Atom Interferometer Gravitation Antenna (ZAIGA) is a new type of underground laser-linked interferometer facility, and is currently under construction. It is in the 200-meter-on-average underground of a mountain named Zhaoshan ... More

Time reversal invariance violation in neutron-nucleus scatteringMar 21 2019Planning and interpretation of the experiments searching for the time reversal (T) and parity (P) violation in neutron reactions require values of the matrix elements of the T,P-violating nuclear forces between nuclear compound states. We calculate the ... More

Calculations of Bethe logarithms for Hydrogen and Helium atoms using B-splines in different gaugesMar 21 2019The efficient and simple B-splines variational method of calculating the hydrogen atom Bethe logarithms in the acceleration gauge [Y-B Tang et.al., Phys. Rev. A $\mathbf{87}$, 022510 (2013)] is successfully applied to other gauges. The ground state Bethe ... More

Electric-field induced helium-helium resonancesMar 20 2019The tunability of the helium-helium interaction through an external electric field is investigated. For a static external field, electric-field induced resonances and associated electric-field induced bound states are calculated for the $^4$He-$^4$He, ... More

How to observe the vacuum decay in low-energy heavy-ion collisionsMar 20 2019In slow collisions of two bare nuclei with the total charge larger than the critical value $Z_{\rm cr} \approx 173$, the initially neutral vacuum can spontaneously decay into the charged vacuum and two positrons. Detection of the spontaneous emission ... More