Hannover 2016 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 21: Matter Wave Optics
Q 21.4: Talk
Tuesday, March 1, 2016, 15:15–15:30, a310
Quantum reflection and Liouville transformations — •Gabriel Dufour1,2, Romain Guérout2, Astrid Lambrecht2, and Serge Reynaud2 — 1Institute of Physics, Albert-Ludwigs University, Freiburg, Germany — 2Laboratoire Kastler Brossel, UPMC-Sorbonne Universités, Paris, France
Collisions of ultracold atoms with surfaces are governed by quantum reflection of the atomic matter wave from the attractive Casimir-Polder potential. While no reflection is expected classically, the quantum reflection probability goes to one for slow atoms and weak atom-surface interactions. These counterintuitive results are best understood by performing a Liouville transformation of the Schrödinger equation, which preserves the scattering amplitudes while changing the potential landscape. We discuss the properties of these transformations and introduce a special choice of coordinate which allows one to map the problem of quantum reflection on the Casimir-Polder potential well onto that of reflection on a repulsive wall [1]. Within this new approach, we identify the parameters which determine the reflection probability. These results have implications for the GBAR project at CERN, which aims to measure the acceleration of gravity for a cold antihydrogen atom [2].
[1] G. Dufour, R. Guérout, A. Lambrecht, and S. Reynaud, EPL 110, 30007 (2015), J. Phys. B: At. Mol. Opt. Phys. 48, 155002 (2015).
[2] G. Dufour, D. B. Cassidy, P. Crivelli, P. Debu, A. Lambrecht, V. V. Nesvizhevsky, S. Reynaud, A. Y. Voronin, and T. E. Wall, Advances in High Energy Physics 2015, 379642 (2015).