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The dynamics of thermal and non-thermal lattice deformation of nanometer thick polycrystalline aluminum film has been studied by means of femtosecond (fs) time-resolved electron diffraction. We utilized two different pump wavelengths: 800…

Materials Science · Physics 2017-09-13 Runze Li , Pengfei Zhu , Jie Chen , Jianming Cao , Peter M. Rentzepis , Jie Zhang

We report on a new technique to split an atomic beam coherently with an easily adjustable splitting angle. In our experiment metastable helium atoms in the |{1s2s}^3S_1 M=1> state diffract from a polarization gradient light field formed by…

Atomic Physics · Physics 2013-05-29 K. F. E. M. Domen , M. A. H. M. Jansen , W. van Dijk , K. A. H. van Leeuwen

We present a summary of recent constraints on the value of the fine-structure constant at the epoch of decoupling from the recent observations made by the Wilkinson Microwave Anisotropy Probe (WMAP) satellite. Within the set of models…

Astrophysics · Physics 2008-11-26 G. Rocha , R. Trotta , C. J. A. P. Martins , A. Melchiorri , P. P. Avelino , P. T. P. Viana

We study the Ho$^{14+}$ ion as a candidate for extremely accurate and stable optical atomic clock which is sensitive to the time variation of the fine structure constant. We demonstrate that the proposed system has all desired features…

Atomic Physics · Physics 2015-03-05 V. A. Dzuba , V. V. Flambaum , Hidetoshi Katori

We report a simple technique for stabilization of a laser frequency at the wings of an atomic resonance. The reference signal used for stabilization issues from interference effects obtained in a low-quality cavity filled with a resonant…

Recent astrophysical observations suggest that the value of fine structure constant $\alpha=e^2/\hbar c$ may be slowly increasing with time. This may be due to an increase of $e$ or a decrease of $c$, or both. In this article, we argue from…

High Energy Physics - Theory · Physics 2014-11-18 Saurya Das , Gabor Kunstatter

We report a sequence of continuous phase transformations in iron telluride, Fe1+yTe (y~0.1), which is observed by combining neutron diffraction, magnetic susceptibility, and specific heat measurements on single crystal samples. While a…

Strongly Correlated Electrons · Physics 2012-02-14 I. A. Zaliznyak , Z. J. Xu , J. S. Wen , J. M. Tranquada , G. D. Gu , V. Solovyov , V. N. Glazkov , A. I. Zheludev , V. O. Garlea , M. B. Stone

We show that the relative effect of variation of the fine structure constant in microwave transitions between very close and narrow rotational-hyperfine levels may be enhanced 2-3 orders of magnitude in diatomic molecules like LaS, LaO,…

Atomic Physics · Physics 2009-11-11 V. V. Flambaum

Molecular dipole moments of analytic density-functional theory are investigated. The effect of element-dependent exchange potentials on these moments are examined by comparison with conventional quantum-chemical methods and experiment for…

Other Condensed Matter · Physics 2009-11-11 Brett I. Dunlap , Shashi P. Karna , Rajendra R. Zope , ;

The 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…

The electromagnetic transition between the almost degenerate 5/2+ and 3/2+ states in Th229 is deemed to be very sensitive to potential changes in the fine structure constant alpha. State of the art Hartree-Fock and Hartree-Fock-Bogoliubov…

Nuclear Theory · Physics 2009-08-18 Elena Litvinova , Hans Feldmeier , Jacek Dobaczewski , Victor Flambaum

[O III]$\lambda\lambda$4960,5008 doublet are often the strongest narrow emission lines in starburst galaxies and quasi-stellar objects (QSOs), and thus are a promising probe to possible variation of the fine-structure constant $\alpha$ over…

Astrophysics of Galaxies · Physics 2023-10-30 Ge Li , Luming Sun , Xiangjun Chen , Hongyan Zhou

We present x-ray powder diffraction (XRPD) and neutron diffraction measurements on the slightly underdoped iron pnictide superconductor Ba(1-x)K(x)Fe2As2, Tc = 32K. Below the magnetic transition temperature Tm = 70K, both techniques show an…

Dielectric relaxation and thermal expansion spectroscopy were made for thin polystyrene films in order to measure the temperature $T_{\alpha}$ corresponding to the peak in the loss component of susceptibility due to the $\alpha$-process and…

Soft Condensed Matter · Physics 2007-05-23 Koji Fukao , Yoshihisa Miyamoto

We theoretically study dynamic scalar polarizabilities of the ground and select long-lived excited states of dysprosium, a highly magnetic atom recently laser cooled and trapped. We demonstrate that there are a set of magic wavelengths of…

Atomic Physics · Physics 2015-05-20 V. A. Dzuba , V. V. Flambaum , Benjamin L. Lev

Ever since the first discoveries of the quantum-interference transport in mesoscopic systems, the electron dephasing times, $\tau_\phi$, in the concentrated AuPd alloys have been extensively measured. The samples were made from different…

Mesoscale and Nanoscale Physics · Physics 2007-11-14 J. J. Lin , T. C. Lee , S. W. Wang

We investigate constraints on the time variation of the fine structure constant between the recombination epoch and the present epoch, \Delta\alpha/\alpha \equiv (\alpha_{rec} - \alpha_{now})/\alpha_{now}, from cosmic microwave background…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Masahiro Nakashima , Kazuhide Ichikawa , Ryo Nagata , Jun'ichi Yokoyama

Dipole-dipole interactions lead to frequency shifts that are expected to limit the performance of next-generation atomic clocks. In this work, we compute dipolar frequency shifts accounting for the intrinsic atomic multilevel structure in…

Quantum Gases · Physics 2021-07-07 A. Cidrim , A. Piñeiro Orioli , C. Sanner , R. B. Hutson , J. Ye , R. Bachelard , A. M. Rey

We have remeasured the absolute $1S$-$2S$ transition frequency $\nu_{\rm {H}}$ in atomic hydrogen. A comparison with the result of the previous measurement performed in 1999 sets a limit of $(-29\pm 57)$ Hz for the drift of $\nu_{\rm {H}}$…

We have trapped cesium atoms over many minutes in the focus of a CO$_2$-laser beam employing an extremely simple laser system. Collisional properties of the unpolarized atoms in their electronic ground state are investigated. Inelastic…

Atomic Physics · Physics 2009-11-06 H. Engler , T. Weber , M. Mudrich , R. Grimm , M. Weidemueller
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