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Université de Fribourg

The wave-particle duality of light: A demonstration experiment

Dimitrova, T. L. ; Weis, Antoine

In: American Journal of Physics, 2008, vol. 76, no. 2, p. 137-142

The wave-particle duality of light plays a fundamental role in introductory courses on quantum mechanics. Traditionally the wave and particle aspects of light are demonstrated in separate experiments which makes it difficult for students to understand their complementary nature. We present an experiment using a single apparatus that demonstrates the wave aspect, the particle aspect, and most...

Université de Fribourg

Towards a new measurement of the neutron electric dipole moment

Altarev, I. ; Ban, G. ; Bison, Georg ; Bodek, K. ; Burghoff, M. ; Cvijovic, Milan ; Daum, M. ; Fierlinger, P. ; Gutsmiedl, E. ; Hampel, G. ; Heil, W. ; Henneck, R. ; Horras, M. ; Khomutov, N. ; Kirch, K. ; Kistryn, S. ; Knappe-Grüneberg, S. ; Knecht, A. ; Knowles, Paul E. ; Kozela, A. ; Kratz, J. V. ; Kuchler, F. ; Kuźniak, M. ; Lauer, T. ; Lauss, B. ; Lefort, T. ; Mtchedlishvili, A. ; Naviliat-Cuncic, O. ; Paul, S. ; Pazgalev, Anatoly S. ; Petzoldt, G. ; Pierre, E. ; Plonka-Spehr, C. ; Quéméner, G. ; Rebreyend, D. ; Roccia, S. ; Rogel, G. ; Sander-Thoemmes, T. ; Schnabel, A. ; Severijns, N. ; Sobolev, Yu. ; Stoepler, R. ; Trahms, L. ; Weis, Antoine ; Wiehl, N. ; Zejma, J. ; Zsigmond, G.

In: Nuclear Instruments and Methods in Physics Research Section A, 2009, p. -

The effort towards a new measurement of the neutron electric dipole moment (nEDM) at the Paul Scherrer Institut's (PSI) new high intensity source of ultracold neutrons (UCN) is described. The experimental technique relies on Ramsey's method of separated oscillatory fields, using UCN in vacuum with the apparatus at ambient temperature. In the first phase, R&D towards the upgrade of the...

Université de Fribourg

Towards a new measurement of the neutron electric dipole moment

Ban, G. ; Bodek, K. ; Daum, M. ; Henneck, R. ; Heule, S. ; Kasprzak, M. ; Khomytov, N. ; Kirch, K. ; Knecht, A. ; Kistryn, S. ; Knowles, Paul E. ; Kuzniak, M. ; Lefort, T. ; Naviliat-Cuncic, O. ; Pichlmaier, A. ; Plonka, C. ; Quéméner, G. ; Rebetez, Martin ; Rebreyend, D. ; Rogel, G. ; Sabirov, B. M. ; Tur, M. ; Weis, Antoine ; Zejma, J.

In: Hyperfine Interactions, 2006, vol. 172, no. 1-3, p. 41-43

Precision measurements of particle electric dipole moments (EDMs) provide extremely sensitive means to search for non-standard mechanisms of T (or CP) violation. For the neutron EDM, the upper limit has been reduced by eight orders of magnitude in 50 years thereby excluding several CP violation scenarios. We report here on a new effort aiming at improving the neutron EDM limit by two orders of...

Université de Fribourg

Theory of double resonance magnetometers based on atomic alignment

Weis, Antoine ; Bison, Georg ; Pazgalev, Anatoly S.

In: Physical Review A, 2006, p. 033401

We present a theoretical study of the spectra produced by optical–radio-frequency double resonance devices, in which resonant linearly polarized light is used in the optical pumping and detection processes. We extend previous work by presenting algebraic results which are valid for atomic states with arbitrary angular momenta, arbitrary rf intensities, and arbitrary geometries. The only...

Université de Fribourg

Test of Lorentz invariance with spin precession of ultracold neutrons

Altarev, I. ; Baker, C. A. ; Ban, G. ; Bison, Georg ; Bodek, K. ; Daum, M. ; Fierlinger, P. ; Geltenbort, P. ; Green, K. ; Grinten, M. G. D. van der ; Gutsmiedl, E. ; Harris, P. G. ; Heil, W. ; Henneck, R. ; Horras, M. ; Iaydjiev, P. ; Ivanov, S. N. ; Khomutov, N. ; Kirch, K. ; Kistryn, S. ; Knecht, A. ; Knowles, Paul E. ; Kozela, A. ; Kuchler, F. ; Kuźniak, M. ; Lauer, T. ; Lauss, B. ; Lefort, T. ; Mtchedlishvili, A. ; Naviliat-Cuncic, O. ; Pazgalev, Anatoly ; Pendlebury, J. M. ; Petzoldt, G. ; Pierre, E. ; Pignol, G. ; Quéméner, G. ; Rebetez, Martin ; Rebreyend, D. ; Roccia, S. ; Rogel, G. ; Severijns, N. ; Shiers, D. ; Sobolev, Yu. ; Weis, Antoine ; Zejma, J. ; Zsigmond, G.

In: Physical Review Letters, 2009, vol. 103, no. 8, p. 081602

A clock comparison experiment, analyzing the ratio of spin precession frequencies of stored ultracold neutrons and ¹⁹⁹Hg atoms, is reported. No daily variation of this ratio could be found, from which is set an upper limit on the Lorentz invariance violating cosmic anisotropy field b⊥<2×10⁻²⁰ eV (95% C.L.). This is the first limit for the free neutron. This result...

Université de Fribourg

Testing isotropy of the universe using the Ramsey resonance technique on ultracold neutron spins

Altarev, I. ; Ban, G. ; Bison, Georg ; Bodek, K. ; Daum, M. ; Fertl, M. ; Fierlinger, P. ; Franke, B. ; Gutsmiedl, E. ; Heil, W. ; Henneck, R. ; Horras, M. ; Khomutov, N. ; Kirch, K. ; Kistryn, S. ; Kraft, A. ; Knecht, A. ; Knowles, Paul E. ; Kozela, A. ; Lauer, T. ; Lauss, B. ; Lefort, T. ; Lemière, Y. ; Mtchedlishvili, A. ; Naviliat-Cuncic, O. ; Pazgalev, Anatoly S. ; Petzoldt, G. ; Piegsa, F.M. ; Pierre, E. ; Pignol, G. ; Quéméner, G. ; Rebetez, M. ; Rebreyend, D. ; Roccia, S. ; Schmidt-Wellenburg, P. ; Severijns, N. ; Sobolev, Yu. ; Weis, Antoine ; Zejma, J. ; Zenner, J. ; Zsigmond, G.

In: Physica B: Condensed Matter, 2011, vol. 406, no. 12, p. 2365-2369

Physics at the Planck scale could be revealed by looking for tiny violations of fundamental symmetries in low energy experiments. In 2008, a sensitive test of the isotropy of the universe has been performed with stored ultracold neutrons (UCN), this is the first clock-comparison experiment performed with free neutrons. During several days we monitored the Larmor frequency of neutron spins in a...

Université de Fribourg

Study of ³He Rabi nutations by optically-pumped cesium magnetometers

Koch, Hans-Christian ; Bison, Georg ; Grujiæ, Zoran Dragan ; Heil, Werner ; Kasprzak, Malgorzata ; Knowles, Paul ; Kraft, Andreas ; Pazgalev, Anatoly ; Schnabel, Allard ; Voigt, Jens ; Weis, Antoine

In: The European Physical Journal D, 2017, vol. 71, no. 10, p. 262

We describe a method for recording the Rabi nutation of nuclear spin polarized ³He by optically pumped cesium magnetometers. The measurement is performed by detecting the time-dependent magnetic field produced by the 3He magnetization. The observed signals are compared to theoretical models and the results are used to precisely trace the evolution of the magnetization. This procedure...

Université de Fribourg

Stark shift of the Cs clock transition frequency: a new experimental approach

Robyr, J.-P. ; Knowles, Paul E. ; Weis, Antoine

In: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 2010, vol. 57, no. 3, p. 613 - 617

The blackbody radiation shift, a manifestation of the Stark effect caused by blackbody radiation, contributes to the systematic uncertainty in Cs-based frequency standards at a level of 1 x 10⁻¹⁵. Few measurements of the third-order scalar electric polarizability of the Cs ground states, mainly responsible for the ac Stark shift in atomic clocks, have given better than 10% accuracy. We...

Université de Fribourg

Spectroscopy of Rb₂ dimers in solid ⁴He

Moroshkin, Peter ; Hofer, Adrian ; Ulzega, Simone ; Weis, Antoine

In: Physical Review A, 2006, vol. 74, p. 032504

We present experimental and theoretical studies of the absorption, emission, and photodissociation spectra of Rb₂ molecules in solid helium. We have identified 11 absorption bands of Rb₂. All laser-excited molecular states are quenched by the interaction with the He matrix. The quenching results in efficient population of a metastable (1) ³πu state, which emits...