Regensburg 2016 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 7: Cold Atomic Gases

TT 7.3: Vortrag

Montag, 7. März 2016, 10:45–11:00, H18

Sudden expansion and domain-wall melting of strongly interacting bosons in 2D optical lattices and on multileg ladders — •Johannes Hauschild¹, Frank Pollmann¹, and Fabian Heidrich-Meisner² — ¹Max Planck Institute for the Physics of Complex Systems, D-01187 Dresden, Germany — ²Department of Physics and Arnold Sommerfeld Center for Theoretical Physics, Ludwig-Maximilians-Universität München, D-80333 München, Germany

We numerically investigate the expansion of clouds of hard-core bosons in a 2D square lattice using a matrix-product state based method. This non-equilibrium setup is induced by quenching the trapping potential to zero and is specifically motivated by recent experiments [1]. As the anisotropy of the amplitudes J_x and J_y for hopping in different spatial directions is varied from 1D to 2D, we observe a crossover from a fast ballistic expansion in the 1D limit J_x ≫ J_y to much slower dynamics in the isotropic 2D limit. We further compare the expansion of a cloud on multileg ladders and long cylinders with the melting of a domain wall and discuss the scenario of a condensation at finite momenta [2].

In addition, we study the domain-wall melting in the presence of a random on-site chemical potential. Tuning the inter-chain coupling J_y allows then to study the transition from an Anderson insulator in 1D to a many-body localized state in 2D.
J. P. Ronzheimer et al., PRL 110, 205301 (2013)
J. Hauschild et al., PRA 92, 053629 (2015)