Berlin 2005 – scientific programme

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Q: Quantenoptik und Photonik

Q 50: Quantengase III

Q 50.1: Talk

Tuesday, March 8, 2005, 18:00–18:15, HU Kinosaal

Density wave packets of ultracold bosonic atoms in an optical lattice using adaptive t-DMRG — •Corinna Kollath^1,2, Ulrich Schollwöck¹, Jan von Delft², and Wilhelm Zwerger³ — ¹Institut für theoretische Physik, RWTH Aachen — ²Sektion Physik, LMU München — ³Institute for Theoretical Physics, Universität Innsbruck

We investigate the propagation of density wave packets in a Bose-Hubbard model using the adaptive time-dependent density-matrix renormalization group method (adaptive t-DMRG). This is a theoretical model for the propagation of a density perturbation in ultra-cold bosons subjected to an optical lattice. We discuss the decay of the amplitude, the dependence of the velocity, in particular the sound velocity, on the background density, the interaction strength and the height of the perturbation in a quasiexact calculation. packet. By comparing the sound velocity to theoretical predictions we determine the limits of the hydrodynamical approach and of the continuum limit in describing the physics generated by the Bose-Hubbard model.