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A: Atomphysik
A 17: Postersitzung 2
A 17.35: Poster
Donnerstag, 27. März 2003, 16:00–18:30, Poster
Bloch oscillations of cold atoms in 1D and 2D optical lattices — •S. Mossmann1, A. R. Kolovsky2, and H. J. Korsch1 — 1Technische Universität Kaiserslautern: FB Physik, D-67653 Kaiserslautern, Germany — 2Max-Planck-Institut für Physik Komplexer Systeme, D-01187 Dresden, Germany
The quantum dynamics of cold atoms in optical lattices under a constant force shows a counterintuitive periodic motion, the Bloch oscillation. Here we discuss the properties of this oscillation in detail, in particular the up to now unexplored two-dimensional case. Here the wavepacket dynamics depends sensitively on the field direction; Lissajous-like motion can be generated. In addition, a modification of the lattice, where, e.g., every second potential well is slightly deepened, leads to a splitting of the original bands. In particular, a gap is opened in the ground band, which leads to pronounced Zener tunneling between these bands and changes the Bloch oscillation into a coherent wavepacket motion on two surfaces. Such a Bloch-Zener oscillation shows interesting features especially in 2D, where such potentials can be experimentally realized by optical lattices.