Atomic Physics
Probing Nonlocal Spatial Correlations in Quantum Gases with Ultra-long-range Rydberg Molecules (1903.11526v1)
J. D. Whalen, S. K. Kanungo, R. Ding, M. Wagner, R. Schmidt, H. R. Sadeghpour, S. Yoshida, J. Burgdörfer, F. B. Dunning, T. C. Killian
2019-03-27
We 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 wavefunction
. By varying the principal quantum number
of the target Rydberg state, the molecular excitation rate can be used to map the pair-correlation function of the trapped gas
. We demonstrate this with ultracold Sr gases and probe pair-separation length scales ranging from
, which are on the order of the thermal de Broglie wavelength for temperatures around 1
K. We observe bunching for a single-component Bose gas of
Sr and anti-bunching due to Pauli exclusion at short distances for a polarized Fermi gas of
Sr, revealing the effects of quantum statistics.
A Frenet-Serret Interpretation of Particle Dynamics in High-Intensity Laser Fields (1903.11463v1)
D. Seipt, A. G. R. Thomas
2019-03-27
In 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 scalars and basis vectors relevant for high-intensity laser particle interactions. The onset of quantum effects relates to the curvature radius of classical trajectories being on the order of the Compton wavelength. The effects of classical radiation reaction are discussed, as well as the classical precession of the spin-polarization vector according to the Thomas-Bargman-Michel-Telegdi (T-BMT) equation. We comment on the derivation of the photon emission rate in strong-field QED beyond the locally constant field approximation, which is used in Monte Carlo simulations of quantum radiation reaction. Such a numerical simulation is presented for a possible experiment to distinguish between classical and quantum mechanical models of radiation reaction.
Simulations of Majorana spin flips in an antihydrogen trap (1903.11443v1)
M. A. Alarcón, C. J. Riggert, F. Robicheaux
2019-03-27
The properties of antihydrogen (
) have, thus far, been probed at magnetic fields of
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 of the
-field. The number and properties of the magnetic field zeros are investigated. For typical magnetic field geometries in
Compact laser system for a laser-cooled ytterbium ion microwave frequency standard (1811.10451v2)
S. Mulholland, H. A. Klein, G. P. Barwood, S. Donnellan, P. B. R. Nisbet-Jones, G. Huang, G. Walsh, P. E. G. Baird, P. Gill
2018-11-26
The development of a transportable microwave frequency standard based on the ground-state transition of
at ~12.6 GHz requires a compact laser system for cooling the ions, clearing out of long-lived states and also for photoionisation. In this paper, we describe the development of a suitable compact laser system based on a 6U height rack-mounted arrangement with overall dimensions
mm. Laser outputs at 369 nm (for cooling), 399 nm (photoionisation), 935 nm (repumping) and 760 nm (state clearout) are combined in a fiber arrangement for delivery to our linear ion trap and we demonstrate this system by cooling of
Compact Optical Atomic Clock Based on a Two-Photon Transition in Rubidium (1903.11231v1)
Kyle W. Martin, Gretchen Phelps, Nathan D. Lemke, Matthew S. Bigelow, Benjamin Stuhl, Michael Wojcik, Michael Holt, Ian Coddington, Michael W. Bishop, Johh H. Burke
2019-03-27
Extra-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 and manufacturable architecture, that utilizes the 778~nm two-photon transition in rubidium and yields fractional frequency instabilities of
for
from 1~s to 10000~s. We present a complete stability budget for this system and explore the required conditions under which a fractional frequency instability of
can be maintained on long timescales. We provide precise characterization of the leading sensitivities to external processes including magnetic fields and fluctuations of the vapor cell temperature and 778~nm laser power. The system is constructed primarily from commercially-available components, an attractive feature from the standpoint of commercialization and deployment of optical frequency standards.
Theoretical study of electron structure of superheavy elements with an open 
-shell, Sg, Bh, Hs and Mt (1902.06819v2)
B. G. C. Lackenby, V. A. Dzuba, V. V. Flambaum
2019-02-18
We use recently developed efficient versions of the configuration interaction method to perform {\em ab initio} calculations of the spectra of superheavy elements seaborgium (Sg,
), bohrium (Bh,
), hassium (Hs,
) and meitnerium (Mt,
). We calculate energy levels, ionization potentials, isotope shifts and electric dipole transition amplitudes. Comparison with lighter analogs reveals significant differences caused by strong relativistic effects in superheavy elements. Very large spin-orbit interaction distinguishes subshells containing orbitals with a definite total electron angular momentum
. This effect replaces Hund's rule holding for lighter elements.
ZAIGA: Zhaoshan Long-baseline Atom Interferometer Gravitation Antenna (1903.09288v2)
Ming-Sheng Zhan, Jin Wang, Wei-Tou Ni, Dong-Feng Gao, Gang Wang, Ling-Xiang He, Run-Bing Li, Lin Zhou, Xi Chen, Jia-Qi Zhong, Biao Tang, Zhan-Wei Yao, Lei Zhu, Zong-Yuan Xiong, Si-Bin Lu, Geng-Hua Yu, Qun-Feng Cheng, Min Liu, Yu-Rong Liang, Peng Xu, Xiao-Dong He, Min Ke, Zheng Tan, Jun Luo
2019-03-22
The 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 which is about 80 km southeast to Wuhan. ZAIGA will be equipped with long-baseline atom interferometers, high-precision atom clocks, and large-scale gyros. ZAIGA facility will take an equilateral triangle configuration with two 1-km-apart atom interferometers in each arm, a 300-meter vertical tunnel with atom fountain and atom clocks mounted, and a tracking-and-ranging 1-km-arm-length prototype with lattice optical clocks linked by locked lasers. The ZAIGA facility will be used for experimental research on gravitation and related problems including gravitational wave detection, high-precision test of the equivalence principle of micro-particles, clock based gravitational red-shift measurement, rotation measurement and gravito-magnetic effect.
Non-adiabatic Storage of Short Light Pulses in an Atom-Cavity System (1903.10922v1)
Tobias Macha, Eduardo Uruñuela, Wolfgang Alt, Maximilian Ammenwerth, Deepak Pandey, Hannes Pfeifer, Dieter Meschede
2019-03-26
We demonstrate the storage of
~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 numerical simulation of our system. We measure storage efficiencies of
, in close agreement with the maximum expected efficiency. Such well-controlled and high-bandwidth atom-photon interfaces are an attractive technology for future hybrid quantum networks.
Single-beam Zeeman slower and magneto-optical trap using a nanofabricated grating (1811.09180v2)
D. S. Barker, E. B. Norrgard, N. N. Klimov, J. A. Fedchak, J. Scherschligt, S. Eckel
2018-11-22
We demonstrate a compact (0.25 L) system for laser cooling and trapping atoms from a heated dispenser source. Our system uses a nanofabricated diffraction grating to generate a magneto-optical trap (MOT) using a single input laser beam. An aperture in the grating allows atoms from the dispenser to be loaded from behind the chip, increasing the interaction distance of atoms with the cooling light. To take full advantage of this increased distance, we extend the magnetic field gradient of the MOT to create a Zeeman slower. The MOT traps approximately
Li atoms emitted from an effusive source with loading rates in excess of
. Our design is portable to a variety of atomic and molecular species and could be a principal component of miniaturized cold-atom-based technologies.
Application of the time-dependent surface flux method to the time-dependent multiconfiguration self-consistent-field method (1903.10743v1)
Yuki Orimo, Takeshi Sato, Kenichi L. Ishikawa
2019-03-26
We 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 (TD-MCSCF) method. Extending the original tSURFF method developed for single particle systems, we formulate the equations of motion for the spectral amplitude of orbital functions constutiting the TD-MCSCF wave function, from which the angle-resolved photoelectron energy spectrum, and more generally, photoelectron reduced density matrices (RDMs) are readiliy obtained. The tSURFF method applied to the TD-MCSCF wave function, in combination with an efficient absorbing boundary offered by the infinite-range exterior complex scaling, enables accurate {\it ab initio} computations of photoelectron energy spectra from multielectron systems subject to an intense and ultrashort laser pulse with a computational cost significantly reduced compared to that required in projecting the total wave function onto scattering states. We apply the present implementation to the photoionization of Ne exposed to an attosecond extreme-ultraviolet (XUV) pulse and above-threshold ionization of Ar irradiated by an intense mid-infrared laser field, demonstrating both accuracy and efficiency of the present method.
