Düsseldorf 2007 – wissenschaftliches Programm

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Q: Fachverband Quantenoptik und Photonik

Q 21: Quanteneffekte (Offene und Wenigteilchensysteme)

Q 21.7: Vortrag

Dienstag, 20. März 2007, 12:00–12:15, 5E

AC-control of single particle tunneling — •Elisabeth Kierig, Arne Schietinger, Ute Schnorrberger, Jiri Tomkovic, Joachim Welte, and Markus Oberthaler — Kirchhoff-Institut für Physik, Universität Heidelberg, Im Neuenheimer Feld 227, 69120 Heidelberg

We report on the results of our experimental studies of periodically driven quantum tunneling systems. By changing the symmetry of the double-well at a special frequency it is possible to strongly suppress tunneling. This effect is known as coherent destruction of tunneling [1].

The experimental setup utilizes a slow intensive beam of metastable argon atoms combined with spatially resolved single atom detection.The periodic double-well potential is realized adding two standing light waves with periodicity λ and λ/2. A further standing light wave resonant with an open transition allows the preparation of atoms localized in every second well. The driving is implemented by changing the phase between the two standing light waves creating the double-wells.

We compare our experimental findings with the full solution of the Floquet theory and the prediction within the simple two mode model. We find quantitative agreement of the tunneling time as a function of driving frequency and driving amplitude.

[1] F. Grossmann, T. Dittrich, P. Jung, and P. Hänggi, Phys. Rev. Lett. 67, 516 (1991)