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Measuring Electromagnetic and Gravitational Responses of Photonic Landau LevelsFeb 13 2018The topology of an object describes global properties that are insensitive to local perturbations. Classic examples include string knots and the genus (number of handles) of a surface: no manipulation of a closed string short of cutting it changes its ... More

Remote sensing of geomagnetic fields and atomic collisions in the mesosphereFeb 09 2018Magnetic-field sensing has contributed to the formulation of the plate-tectonics theory, the discovery and mapping of underground structures on Earth, and the study of magnetism in other planets. Filling the gap between space-based and near-Earth observation, ... More

Lattice-induced photon scattering in an optical lattice clockFeb 08 2018We investigate scattering of lattice laser radiation in a strontium optical lattice clock and its implications for operating clocks at interrogation times up to several ten seconds. Rayleigh scattering does not cause significant decoherence of the atomic ... More

One-center calculations of the electron-positron pair creation in low-energy collisions of heavy bare nucleiFeb 08 2018The probabilities of bound-free electron-positron pair creation are calculated for head-on collisions of bare uranium nuclei beyond the monopole approximation. The calculations are based on the numerical solving of the time-dependent Dirac equation in ... More

Determination of the He-He, Ne-Ne, Ar-Ar, and H$_{2}$ interaction potential by wave function imagingFeb 08 2018We report on a direct method to measure the internuclear potential energy curve of diatomic systems. A COLTRIMS reaction microscope was used to measure the squares of the vibrational wave functions of H$_{2}$, He$_{2}$, Ne$_{2}$, and Ar$_{2}$. The Schr\"odinger ... More

Ultraviolet laser spectroscopy of aluminum atoms in hollow-cathode lampFeb 08 2018We report precision measurement of aluminum atoms ${^{2}P_{1/2}}-{^{2}S_{1/2}}$ transition at 394 nm and ${^{2}P_{3/2}}-{^{2}S_{1/2}}$ transition at 396 nm in a hollow-cathode lamp (HCL). Both absorption spectroscopy and saturated absorption spectroscopy ... More

Relativistic coupled-cluster theory analysis of energies, hyperfine structure constants, and dipole polarizabilities of Cd$^{+}$Feb 08 2018Roles of electron correlation effects in the determination of attachment energies, magnetic dipole hyperfine structure constants and electric dipole (E1) matrix elements of the low-lying states in the singly charged cadmium ion (Cd$^+$) have been analyzed. ... More

Paraffin coated rubidium cell with an internal atomic vapor sourceFeb 08 2018We present the results of a study on relaxation and diffusion processes of rubidium atoms in a rubidium cell with an internal vapor source. The cell is an evacuated glass bulb, which is characterized in that the source of atomic vapors in the form of ... More

A low phase noise microwave frequency synthesizer based on parameters optimized NLTL for Cs fountain clockFeb 08 2018We report on the development and phase noise performance of a 9.1926 GHz microwave frequency synthesizer to be used as the local oscillator for a Cs fountain clock. It is based on frequency multiplication and synthesis from an ultralow phase noise 5 MHz ... More

Gauge-invariant formulation of time-dependent configuration interaction singles methodFeb 07 2018Feb 08 2018We propose a gauge-invariant formulation of the channel orbital-based time-dependent configuration interaction singles (TDCIS) method [Phys. Rev. A 74, 043420 (2006)], one of the powerful ab initio methods to investigate electron dynamics in atoms and ... More

Management of the Correlations of Ultracold Bosons in Triple WellsFeb 07 2018Ultracold interacting atoms are an excellent tool to study correlation functions of many-body systems that are generally eluding detection and manipulation. Herein, we investigate the ground state of bosons in a tilted triple-well potential and characterize ... More

Velocimetry of cold atoms by matterwave interferometryFeb 06 2018We present a method for the velocimetry of cold atoms by matterwave interferometry, which we have used to measure the velocity distributions within freely-expanding clouds of $^{85}$Rb atoms at temperatures of 17 and 33 $\mu$K. Quadrature measurement ... More

Model-independent determinations of the electron EDM and the role of diamagnetic atomsFeb 06 2018We perform model-independent analyses extracting limits for the electric dipole moment of the electron and the P,T-odd scalar-pseudoscalar (S-PS) nucleon-electron coupling from the most recent measurements with atoms and molecules. The analysis using ... More

Moiré patterns in doubly differential electron momentum distributions in atomic ionization by midinfrared lasersFeb 06 2018We analyze the doubly differential electron momentum distribution in above-threshold ionization of atomic hydrogen by a linearly-polarized mid-infrared laser pulse. We reproduce side rings in the momentum distribution with forward-backward symmetry previously ... More

Hyperspherical-LOCV Approximation to Resonant BECFeb 06 2018We study the ground state properties of a system of $N$ harmonically trapped bosons of mass $m$ interacting with two-body contact interactions, from small to large scattering lengths. This is accomplished in a hyperspherical coordinate system that is ... More

Comparison of Hartree-Fock and local density exchange appr oximations for calculation of radiation damage dynamics of light and heavy atoms in the field of x-ray free electron laserFeb 06 2018Simulations of radiation damage in single molecule imaging using X-ray free electron laser use atomic rates calculated in the lowest order. We investigate the difference in ion yield predictions using Hartree-Fock and local density approximation for lig ... More

Continuous Production of Rovibronic Ground State RbCs Molecules via Short-Range Photoassociation to the $b^3Π_{1}-c^3Σ^+_{1}-B^1Π_1$ StatesFeb 06 2018We have investigated rovibronic levels of the strongly mixed $b^3\Pi_1-c^3\Sigma^+_1-B^1\Pi_1$ states [the 2(1), 3(1), and 4(1) states in Hund's case (c) notation] of $^{85}$Rb$^{133}$Cs in the energy range of 13950$-$14200 cm$^{-1}$ using short-range ... More

Diffraction of a CW atom laser in the Raman-Nath regimeFeb 05 2018Atom interferometry is the most successful technique for precision metrology. However, current interferometers using ultracold atoms allows one to probe the interference pattern only momentarily and has finite duty cycle, resulting in an aliasing effect ... More

Coulomb-free and Coulomb-distorted recolliding quantum orbits in photoelectron holographyFeb 02 2018We perform a detailed analysis of the different types of orbits in the Coulomb Quantum Orbit Strong-field Approximation (CQSFA), ranging from direct to those undergoing hard collisions. We show that some of them exhibit clear counterparts in the standard ... More

A method for model-independent measurement of the CKM angle $β$ via time-dependent analysis of the $B^0\to Dπ^+π^-$, $D\to K_S^0π^+π^-$ decaysFeb 01 2018A new method for model-independent measurement of the CKM angle $\beta$ is proposed, that employs time-dependent analysis of flavour-tagged $B^0\to D\pi^+\pi^-$ decays with $D$ meson decays into CP-specific and~$K_S^0\pi^+\pi^-$ final states. This method ... More

Studying Antimatter Gravity with MuoniumFeb 01 2018Feb 07 2018The gravitational acceleration of antimatter, gbar, has yet to be directly measured; an unexpected outcome of its measurement could change our understanding of gravity, the universe, and the possibility of a fifth force. Three avenues are apparent for ... More

Atomic-state diagnostics and optimization in cold-atom experimentsJan 31 2018Feb 02 2018We report on the creation, observation and optimization of superposition states of cold atoms. In our experiments, rubidium atoms are prepared in a magneto-optical trap and later, after switching off the trapping fields, Faraday rotation of a weak probe ... More

Hyperfine interaction with the $^{229}$Th nucleus and its low lying isomeric stateJan 31 2018The thorium nucleus with mass number $A=229$ has attracted much interest because its extremely low lying first excited isomeric state at about $8$eV opens the possibility for the development of a nuclear clock. However, neither the exact energy of this ... More

Measurement of differential polarizabilities at a mid-infrared wavelength in $^{171}\mathrm{Yb}^+$Jan 30 2018An atom exposed to an electric field will experience Stark shifts of its internal energy levels, proportional to their polarizabilities. In optical frequency metrology, the Stark shift due to background black-body radiation (BBR) modifies the frequency ... More

Development of a new UHV/XHV pressure standard (cold atom vacuum standard)Jan 30 2018The National Institute of Standards and Technology has recently begun a program to develop a primary pressure standard that is based on ultra-cold atoms, covering a pressure range of 1 x 10-6 to 1 x 10-10 Pa and possibly lower. These pressures correspond ... More

Observation of interaction-induced gauge fields in a Bose-Einstein condensate based on micromotion control in a shaken two-dimensional latticeJan 30 2018We demonstrate an interaction-induced gauge field for Bose-Einstein condensates in a modulated two-dimensional optical lattice. The gauge field results from the synchronous coupling between the interactions and micromotion of the atoms. As a first step, ... More

Comparing many-body approaches against the real helium atom exact solutionJan 30 2018Over time, many different theories and approaches have been developed to tackle the many-body problem in quantum chemistry, condensed-matter physics, and nuclear physics. Here we use the real helium atom, rather than a model, and we use the exact solution ... More

Coherent buildup of high harmonic radiation: the classical perspectiveJan 29 2018We present a classical model for high harmonic generation during the propagation of an intense laser pulse through an atomic gas. Numerical simulations of the model show excellent quantitative agreement with the corresponding quantum model for the blueshift ... More

A 3D-printed alkali metal dispenserJan 29 2018We demonstrate and characterize a source of Li atoms made from direct metal laser sintered titanium. The source's outgassing rate is measured to be $5 \,(2)\cdot 10^{-7}$\,$\rm{Pa}~ \rm{L}~ \rm{s}^{-1}$ at a temperature $T=330\,^\circ$C, which optimizes ... More

On loading of a magneto-optical trap on an atom-chip with U-wire quadrupole fieldJan 29 2018Jan 31 2018The role of U-wire generated quadrupole like magnetic field configuration on loading of cold $^{87}Rb$ atoms in a magneto-optical trap (MOT) on atom-chip has been investigated. It is shown by simulations that the quadrupole field profile and the center ... More

Experimental demonstration of shaken lattice interferometryJan 28 2018We experimentally demonstrate a shaken lattice interferometer. Atoms are trapped in the ground Bloch state of a red-detuned optical lattice. Using a closed-loop optimization protocol based on the dCRAB algorithm, we phase-modulate (shake) the lattice ... More

On transversely isotropic mechanical properties of vacancy defected carbon nanotubesJan 27 2018Molecular dynamics (MD) simulations with Adaptive Intermolecular Reactive Empirical Bond Order (AIREBO) force fields were conducted to determine the transversely isotropic elastic properties of carbon nanotubes (CNTs) containing vacancies. This is achieved ... More

New measurement of the $1S-3S$ transition frequency of hydrogen: contribution to the proton charge radius puzzleJan 26 2018We present a new measurement of the $1S-3S$ two-photon transition frequency of hydrogen, realized with a continuous-wave excitation laser at 205 nm on a room-temperature atomic beam, with a relative uncertainty of $9\times10^{-13}$. The proton charge ... More

Cavity enhanced DUV laser for two-photon cooling of atomic hydrogenJan 25 2018We demonstrate a \SI{650}{\mW} \SI{243}{\nm} continuous-wave laser coupled to a linear optical enhancement cavity. The enhancement cavity can maintain $>$\SI{30}{\W} of intracavity power for \SI{1}{\hour} of continuous operation without degradation. This ... More

Ultrafast extreme ultraviolet photoemission without space chargeJan 24 2018Feb 02 2018Time- and Angle-resolved photoelectron spectroscopy from surfaces can be used to record the dynamics of electrons and holes in condensed matter on ultrafast time scales. However, ultrafast photoemission experiments using extreme-ultraviolet (XUV) light ... More

Atom-molecule collisions, spin relaxation, and sympathetic cooling in an ultracold spin-polarized Rb($^2\mathrm{S}$)-SrF$(^2Σ^+)$ mixtureJan 24 2018We explore the suitability of ultracold collisions between spin-polarized SrF($^2\Sigma^+$) molecules and Rb($^2$S) atoms as elementary steps for the sympathetic cooling of SrF($^2\Sigma^+$) molecules in a magnetic trap. To this end, we carry out quantum ... More

Dicke model simulation via cavity-assisted Raman transitionsJan 24 2018The Dicke model is of fundamental importance in quantum mechanics for understanding the collective behaviour of atoms coupled to a single electromagnetic mode. In this paper, we demonstrate a Dicke-model simulation using cavity-assisted Raman transitions ... More

Phase- and intensity-resolved measurements of above threshold ionization by few-cycle pulsesJan 23 2018We investigate the carrier-envelope phase and intensity dependence of the longitudinal momentum distribution of photoelectrons resulting from above-threshold ionization of argon by few-cycle laser pulses. The intensity of the pulses with a center wavelength ... More

Excitation and charge transfer in low-energy hydrogen atom collisions with neutral ironJan 22 2018Data for inelastic processes due to hydrogen atom collisions with iron are needed for accurate modelling of the iron spectrum in late-type stars. Excitation and charge transfer in low-energy Fe+H collisions is studied theoretically using a previously ... More

Relativistic Normal Coupled-Cluster Theory for Accurate Determination of Electric Dipole Moments of Atoms: First application to $^{199}$Hg atomJan 22 2018Recent relativistic coupled-cluster (RCC) calculations of electric dipole moments (EDMs) of diamagnetic atoms due to parity and time-reversal violating (P,T-odd) interactions, that are essential ingredients for probing new physics beyond the standard ... More

Transport of secondary electrons through coatings of ion-irradiated metallic nanoparticlesJan 21 2018Feb 05 2018The transport of low-energy electrons through the coating of a radiosensitizing metallic nanoparticle under fast ion irradiation is analyzed theoretically and numerically. As a case study, we consider a poly(ethylene glycol)-coated gold nanoparticle of ... More

Charge transfer in H + He$^+$ and H$^+$ + He collisions in excited statesJan 21 2018We present a theoretical study of charge transfer in collisions of excited ($n=2,3$) hydrogen atoms with He$^+$ and in collisions of excited ($n=2,3$) helium atoms with H$^+$, extending the results of Phys. Rev. A 82 012708 (2010). A combination of quantum-mechanical ... More

Dynamical process of optically trapped singlet ground state $^{85}$Rb$^{133}$Cs molecules produced via short-range photoassociationJan 18 2018We investigate the dynamical process of optically trapped X$^{1}$$\Sigma$$^{+}$ (v" = 0) state $^{85}$Rb$^{133}$Cs molecules distributing in J" = 1 and J" = 3 rotational states. The considered molecules, formed from short-range photoassociation of mixed ... More

Accurate Determination of the Dynamical Polarizability of DysprosiumJan 17 2018We report a measurement of the dynamical polarizability of dysprosium atoms in their electronic ground state at the optical wavelength of 1064 nm, which is of particular interest for laser trapping experiments. Our method is based on collective oscillations ... More

Experimental study of the role of trap symmetry in an atom-chip interferometer above the Bose-Einstein condensation thresholdJan 16 2018We report the experimental study of an atom-chip interferometer using ultracold rubidium 87 atoms above the Bose-Einstein condensation threshold. The observed dependence of the contrast decay time with temperature and with the degree of symmetry of the ... More

Information-entropic measures in free and confined hydrogen atomJan 16 2018Shannon entropy ($S$), R{\'e}nyi entropy ($R$), Tsallis entropy ($T$), Fisher information ($I$) and Onicescu energy ($E$) have been explored extensively in both \emph{free} H atom (FHA) and \emph{confined} H atom (CHA). For a given quantum state, accurate ... More

Laser-stimulated electric quadrupole transitions in the molecular hydrogen ion H2+Jan 15 2018Jan 16 2018Molecular hydrogen ions are of metrological relevance due to the possibility of precise theoretical evaluation of their spectrum and of external-field-induced shifts. We report the results of the calculations of the rate of laser-induced electric quadrupole ... More

Using Gaussian Basis-Sets with Gaussian Nuclear Charge Distribution to Solve Dirac-Hartree-Fock Equation for 83 Bi-AtomJan 14 2018In this paper, we consider the Dirac-Hartree-Fock equations for system has many-particles. The difficulties associated with Gaussians model are likely to be more complex in relativistic Dirac- Hartree-Fock calculations. To processing these problem, we ... More

Nonlinearity-induced localization in a periodically-driven semi-discrete systemJan 12 2018We demonstrate that nonlinearity plays a constructive role in supporting the robustness of dynamical localization in a model which is discrete, in one dimension and continuous in the orthogonal one. In the linear regime, time-periodic modulation of the ... More

A Rydberg-dressed Magneto-Optical TrapJan 11 2018We propose and demonstrate the laser cooling and trapping of Rydberg-dressed Sr atoms. By off-resonantly coupling the excited state of a narrow (7 kHz) cooling transition to a high-lying Rydberg state, we transfer Rydberg properties such as enhanced electric ... More

Imaging the square of the correlated two-electron wave function of a hydrogen moleculeJan 11 2018The toolbox for imaging molecules is well-equipped today. Some techniques visualize the geometrical structure, others the electron density or electron orbitals. Molecules are many-body systems for which the correlation between the constituents is decisive ... More

Extended calculations of energy levels, radiative properties, $A_{J}$, $B_{J}$ hyperfine interaction constants, and Landé $g_{J}$-factors for nitrogen-like \mbox{Ge XXVI}Jan 11 2018Employing two state-of-the-art methods, multiconfiguration Dirac--Hartree--Fock and second-order many-body perturbation theory, highly accurate calculations are performed for the lowest 272 fine-structure levels arising from the $2s^{2} 2p^{3}$, $2s 2p^{4}$, ... More

Schlieren Imaging for the Determination of the Radius of an Excited Rubidium ColumnJan 10 2018Jan 12 2018AWAKE develops a new plasma wakefield accelerator using the CERN SPS proton bunch as a driver. The proton bunch propagates through a 10 m long rubidium plasma, induced by an ionizing laser pulse. The co-propagation of the laser pulse with the proton bunch ... More

Ultrafast x-ray-induced nuclear dynamics in diatomic molecules using femtosecond x-ray/x-ray pump-probe spectroscopyJan 09 2018The capability of generating two intense, femtosecond x-ray pulses with controlled time delay opens the possibility of performing time-resolved experiments for x-ray induced phenomena. We have applied this capability to study the photoinduced dynamics ... More

Microwave-optical two photon excitation of Rydberg statesJan 08 2018We report efficient microwave-optical two photon excitation of Rb Rydberg atoms in a magneto optical trap. This approach allows the excitation of normally inaccessible states and provides a path toward excitation of high angular momentum states. The efficiency ... More

Interelectronic-interaction correction to the nonlinear Zeeman effect in boronlike ionsJan 08 2018The relativistic calculations of the second- and third-order contributions in magnetic field to the Zeeman splitting in boronlike ions in a wide range of the nuclear charge $Z=6$ - $92$ are presented. The interelectronic-interaction correction of the ... More

Binding energies of the $1s^2\,2s\,2p\, ^3P_{0,2}$ states of berylliumlike xenonJan 07 2018Binding energies of the $^3P_0$ and $^3P_2$ levels of the $1s^2\,2s\,2p$ electron configuration in berylliumlike xenon are rigorously evaluated using ab initio QED approach. All relevant one- and many-electron QED contributions are accounted for up to ... More

Access to improve the muon mass and magnetic moment anomaly via the bound-muon $g$ factorJan 05 2018A theoretical description of the $g$ factor of a muon bound in a nuclear potential is presented. One-loop self-energy and multi-loop vacuum polarization corrections are calculated, taking into account the interaction with the binding potential exactly. ... More

The Collective Lamb Shift of a Nanoscale Atomic Vapour Layer within a Sapphire CavityJan 05 2018Jan 10 2018We measure the near-resonant transmission of light through a dense medium of potassium vapor confined in a cell with nanometer thickness. We observe that the frequency of the minimal transmission first shifts to the blue and then to the red as a function ... More

Spectral Asymmetry of Atoms in the van der Waals Potential of an Optical NanofiberJan 04 2018We measure the modification of the transmission spectra of cold $^{87}$Rb atoms in the proximity of an optical nanofiber (ONF). Van der Waals interactions between the atoms an the ONF surface decrease the resonance frequency of atoms closer to the surface. ... More

Probing resonant energy transfer in collisions of ammonia with Rydberg helium atoms by microwave spectroscopyJan 04 2018We present the results of experiments demonstrating the spectroscopic detection of F\"{o}rster resonance energy transfer from NH$_3$ in the $X\,^1A_1$ ground electronic state to helium atoms in 1s$n$s\,$^3$S$_1$ Rydberg levels, where $n=37$ and $n=40$. ... More

Neutral atom wavelength compatible 780 nm single photons from a trapped ion via quantum frequency conversionJan 03 2018Quantum networks consisting of quantum memories and photonic interconnects can be used for entanglement distribution (L.-M.Duan and H. J. Kimble, PRL 90, 253601 (2003), H. J. Kimble, Nat. 453, 1023 EP (2008)), quantum teleportation (S.Pirandola et.al, ... More

Constraints on exotic spin-dependent interactions between matter and antimatter from antiprotonic helium spectroscopyJan 01 2018Heretofore undiscovered spin-0 or spin-1 bosons can mediate exotic spin-dependent interactions between standard-model particles. Here we carry out the first search for semileptonic spin-dependent interactions between matter and antimatter. We compare ... More

Two-frequency operation of a Paul trap to optimise confinement of two species of ionsJan 01 2018We describe the operation of an electrodynamic ion trap in which the electric quadrupole field oscillates at two frequencies. This mode of operation allows simultaneous tight confinement of ions with extremely different charge-to-mass ratios, e.g., singly ... More

Energy transfer reaction K(4s) + K(7s) \rightarrow K(4s) + K(5f), theory compared with experimentDec 30 2017A comparison between theory and experiment, concerning the K(4s)+K(7s)\rightarrow K(4s)+K(5f) reaction of energy transfer in thermal collisions, is presented. Relevant cross sections are calculated for the potassium vapour temperatures in the range of ... More

Quantum metrology based on strongly correlated matterDec 29 2017We propose and analyze a new method for quantum metrology based on stable non-equilibrium states of quantum matter. Our approach utilizes quantum correlations stabilized by strong interactions and periodic driving. As an example, we present an explicit ... More

Nanoscopy of pairs of atoms by fluorescence in a magnetic fieldDec 29 2017Spontaneous emission spectra of initially excited two closely spaced identical atoms are very sensitive to the strength and direction of the applied magnetic field. The relevant schemes are considered that ensure the determination of the mutual spatial ... More

Emergence of Spatial Order in Highly Interacting Rydberg GasesDec 28 2017We describe the emergence of strong spatial correlations, akin to liquid-like behavior and crystallization effects, in low (one and two) dimensional gases of cold Rydberg atoms. The presence of an external electric field permanently polarizes the atoms, ... More

High-energy $μ^+μ^-$ electroproductionDec 28 2017The cross sections of high-energy $\mu^+\mu^-$ pair production and paradimuonium production by a relativistic electron in the atomic field are discussed. The calculation is performed exactly in the parameters of the atomic field. Though the Coulomb corrections ... More

Integral representation for scattering phase shifts via the phase-amplitude approachDec 27 2017A novel integral representation for scattering phase shifts is obtained based on a modified version of Milne's phase-amplitude approach [W.E. Milne, Phys. Rev. $\mathbf{35}$, 863 (1930)]. We replace Milne's nonlinear differential equation for the amplitude ... More

New ideas for tests of Lorentz invariance with atomic systemsDec 27 2017Dec 29 2017We describe a broadly applicable experimental proposal to search for the violation of local Lorentz invariance (LLI) with atomic systems. The new scheme uses dynamic decoupling and can be implemented in current atomic clocks experiments, both with single ... More

Relativistic configuration-interaction calculations of energy levels of the $1s^22l$ and $1s2l2l'$ states in lithium-like ions: carbon through chlorineDec 26 2017We present systematic calculations of energy levels of the $1s^22l$ and $1s2l2l'$ states of ions along the lithium isoelectronic sequence from carbon till chlorine. The calculations are performed by using the relativistic-configuration-interaction method ... More

Continuous-frequency measurements of high-intensity microwave electric fields with atomic vapor cellsDec 23 2017We demonstrate continuous-frequency electric field measurements of high-intensity microwaves via optical spectroscopy in a small atomic vapor cell. The spectroscopic response of a room-temperature rubidium atomic vapor in a glass cell is investigated ... More

Electromagnetically Induced Transparency (EIT) and Autler-Townes (AT) splitting in the Presence of Band-Limited White Gaussian NoiseDec 22 2017We investigate the effect of band-limited white Gaussian noise (BLWGN) on electromagnetically induced transparency (EIT) and Autler-Townes (AT) splitting, when performing atom-based continuous-wave (CW) radio-frequency (RF) electric (E) field strength ... More

Simultaneous coherence enhancement of optical and microwave transitions in solid-state electronic spinsDec 22 2017Solid-state electronic spins are extensively studied in quantum information science, both for quantum computation, sensing and communication. Electronic spins are highly interesting due to their large magnetic moments, which offer fast operations for ... More

Atomic properties of actinide ions with particle-hole configurationsDec 22 2017We study the effects of higher-order electronic correlations in the systems with particle-hole excited states using a relativistic hybrid method that combines configuration interaction and linearized coupled-cluster approaches. We find the configuration ... More

Ultracold anions for high-precision antihydrogen experimentsDec 22 2017Current and future experiments with antihydrogen ($\overline{\text{H}}$) for a study of matter--antimatter (CPT) symmetry and antimatter gravity require ultracold $\overline{\text{H}}$ in order to reach ultimate levels of precision. A promising path towards ... More

High-precision measurements and theoretical calculations of indium excited-state polarizabilitiesDec 20 2017Dec 23 2017We report measurements of the $^{115}$In $7p_{1/2}$ and $7p_{3/2}$ scalar and tensor polarizabilities using two-step diode laser spectroscopy in an atomic beam. The scalar polarizabilities are one to two orders of magnitude larger than for lower lying ... More

Quantum repeaters with individual rare-earth ions at telecommunication wavelengthsDec 14 2017Dec 18 2017We present a quantum repeater scheme that is based on individual Erbium and Europium ions. Erbium ions are attractive because they emit photons at telecommunication wavelength, while Europium ions offer exceptional spin coherence for long-term storage. ... More

Photon momentum in a distorted optical fieldDec 11 2017In a laser beam, the momentum carried by light is locally affected by spacial intensity and phase fluctuations. In this letter, we show that fluctuations of the momentum is correlated to intensity fluctuations of the beam. We propose a model to estimate ... More

Astrophysical signatures of leptoniumDec 06 2017More than 10^43 positrons annihilate every second in the centre of our Galaxy yet, despite four decades of observations, their origin is still unknown. Many candidates have been proposed, such as supernovae and low mass X-ray binaries. However, these ... More

Lasing from cold ytterbium atomsNov 23 2017Dec 04 2017A few million ytterbium atoms are magneto-optically trapped inside a 5 cm long high-finesse cavity and laterally pumped close to resonance with the narrow $^1$S$_0$ $\to$ $^3$P$_1$ line. Frequency-shifted cavity emission on the same transition is observed ... More

Towards a global quantum networkOct 31 2017The creation of a global quantum network is within reach combining satellite links and quantum memory based approaches. Applications will range from secure communication and fundamental physics experiments to a future quantum internet.

Characterization of the hyperfine interaction of the excited $^5$D$_0$ state of Eu$^{3+}$:Y$_2$SiO$_5$Oct 20 2017We characterize the Europium (Eu$^{3+}$) hyperfine interaction of the excited state ($^5$D$_0$) and determine its effective spin Hamiltonian parameters for the Zeeman and quadrupole tensors. An optical free induction decay method is used to measure all ... More

Anisotropic polarizability of erbium atomsOct 19 2017Oct 20 2017We report on the determination of the dynamical polarizability of ultracold erbium atoms in the ground and in one excited state at three different wavelengths, which are particularly relevant for optical trapping. Our study combines experimental measurements ... More

A cryofuge for cold-collision experiments with slow polar moleculesOct 16 2017Ultracold molecules represent a fascinating research frontier in physics and chemistry, but it has proven challenging to prepare dense samples at low velocities. Here we present a solution to this goal by a non-conventional approach dubbed cryofuge. It ... More

Signatures of electronic structure in bi-circular high-harmonic spectroscopyOct 12 2017High-harmonic spectroscopy driven by circularly-polarized laser pulses and their counter-rotating second harmonic is a new branch of attosecond science which currently lacks quantitative interpretations. We extend this technique to the mid-infrared regime ... More

The ASACUSA antihydrogen and hydrogen program : results and prospectsOct 09 2017The goal of the ASACUSA-CUSP collaboration at the Antiproton Decelerator of CERN is to measure the ground-state hyperfine splitting of antihydrogen using an atomic spectroscopy beamline. A milestone was achieved in 2012 through the detection of 80 antihydrogen ... More

Observation of Feshbach resonances between alkali and closed-shell atomsOct 09 2017Magnetic Feshbach resonances are an invaluable tool for controlling ultracold atoms and molecules. They can be used to tune atomic interactions and have been used extensively to explore few- and many-body phenomena. They can also be used for magnetoassociation, ... More

Carrier-envelope phase controlled isolated attosecond pulses in the nm wavelength range, based on superradiant nonlinear Thomson-backscatteringSep 07 2017Dec 18 2017A proposal for a novel source of isolated attosecond XUV -- soft X-ray pulses with a well controlled carrier-envelope phase difference (CEP) is presented in the framework of nonlinear Thomson-backscattering. Based on the analytic solution of the Newton-Lorentz ... More

Photons and polaritons in a time-reversal-broken non-planar resonatorAug 31 2017Dec 01 2017From generation of backscatter-free transmission lines, to optical isolators, to chiral Hamiltonian dynamics, breaking time-reversal symmetry is a key tool for development of next-generation photonic devices and materials. Of particular importance is ... More

Motional studies of one and two laser-cooled trapped ions for electric-field sensing applicationsAug 22 2017We have studied the dynamics of one and two laser-cooled trapped $^{40}$Ca$^+$ ions by applying electric fields of different nature along the axial direction of the trap, namely, driving the motion with a harmonic dipolar field, or with white noise. These ... More

Suppression of nonlinear Zeeman effect and heading error in earth-field-range alkali-vapor magnetometersAug 17 2017The nonlinear Zeeman effect can induce splitting and asymmetries of magnetic-resonance lines in the geophysical magnetic field range. This is a major source of "heading error" for scalar atomic magnetometers. We demonstrate a method to suppress the nonlinear ... More

Chimera patterns in conservative systems and ultracold atoms with mediated nonlocal hoppingAug 15 2017Chimera patterns, characterized by coexisting regions of phase coherence and incoherence, have so far been studied in non-conservative systems with dissipation. Here, we show that the formation of chimera patterns can also be observed in conservative ... More

Entanglement between two spatially separated atomic modesAug 08 2017Modern quantum technologies in the fields of quantum computing, quantum simulation and quantum metrology require the creation and control of large ensembles of entangled particles. In ultracold ensembles of neutral atoms, highly entangled states containing ... More

Endoscopic imaging of quantum gases through a fiber bundleAug 07 2017We use a coherent fiber bundle to demonstrate the endoscopic absorption imaging of quantum gases. We show that the fiber bundle introduces spurious noise in the picture mainly due to the strong core-to-core coupling. By direct comparison with free-space ... More

AC Stark Effect in Ultracold Polar RbCs MoleculesAug 02 2017We investigate the effect of far-off-resonant trapping light on ultracold bosonic RbCs molecules. We use kHz-precision microwave spectroscopy to measure the differential AC Stark shifts between the ground and first excited rotational levels of the molecule ... More

Observation of Bose-enhanced photoassociation productsAug 01 2017We produce ${^{84}\mathrm{Sr}_2}$ molecules using Bose-enhanced Raman photoassociation. We apply the stimulated Raman adiabatic passage (STIRAP) technique on a Bose-Einstein condensate (BEC) to produce more than $8 \times 10^3$ ultracold molecules. This ... More

Spectroscopic determination of magnetic-field-dependent interactions in an ultracold Yb(3P2)-Li mixtureAug 01 2017Sep 19 2017We present experimental results on the inelastic and elastic interspecies interactions between ytterbium (Yb) in the metastable ${}^3\mathrm{P}_2$ state loaded into a deep optical lattice and spin polarized lithium (Li) in its ground state. Focusing on ... More

Detection of Applied and Ambient Forces with a Matterwave Magnetic-GradiometerJul 24 2017Nov 03 2017An atom interferometer using a Bose-Einstein condensate of $^{87}$Rb atoms is utilized for the measurement of magnetic field gradients. Composite optical pulses are used to construct a spatially symmetric Mach-Zehnder geometry. Using a biased interferometer ... More