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Q: Quantenoptik und Photonik
Q 10: Quanteneffekte I
Q 10.7: Vortrag
Montag, 13. März 2006, 15:30–15:45, HII
Quantum Reflection of thermal atoms from nano-crafted structures — •Ulrich Warring — Physikalisches Institut Heidelberg, Philosophen Weg 12, 69120 Heidelberg
In the Heidelberger Atomic Beam Spin Echo (ABSE) spectrometer, we have recently succeeded to detect Quantum Reflection (QR) of 3He atoms from plain and well-characterized surfaces. For semi-conductors, we find that QR takes place at the transition from the van der Waals dominated part of the interaction potential to the Casimir-Polder part. In order to investigate the topological aspects of the Casimir-Polder force, we studied QR from different gratings. Depending on the shape and the orientation of these nano-structures, dramatic changes in reflectivity were observed. Quantitatively, the data are explained by an earlier breakdown of the WKB-approximation. Observed dispersion in the reflected intensity is quantitatively explained in terms of Quantum Diffraction.