Berlin 2014 – wissenschaftliches Programm
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A: Fachverband Atomphysik
A 52: Characterization and control of complex quantum systems SYQS 1 (with Q, MO, MS, MP, AGjDPG)
A 52.4: Vortrag
Freitag, 21. März 2014, 12:15–12:30, Audimax
Tuning the Quantum Phase Transition of Bosons in Optical Lattices via Periodic Modulation of s-Wave Scattering Length — Tao Wang1,2, •Xue-Feng Zhang1, Francisco Ednilson Alves dos Santos3, Sebastian Eggert1, and Axel Pelster1 — 1Physics Department and Research Center OPTIMAS, Technische Universität Kaiserslautern, Germany — 2Department of Physics, Harbin Institute of Technology, China — 3Instituto de Física de São Carlos, Universidade São Paulo, Brazil
We investigate how the superfluid-Mott insulator quantum phase transition for bosons in a 2D square and a 3D cubic optical lattice changes due to a periodic modulation of the s-wave scattering length. At first we map the underlying periodically driven Bose-Hubbard model approximately to an effective time-independent Hamiltonian with a conditional hopping [1]. Combining different analytical approaches with quantum Monte Carlo simulations then reveals that the location of the quantum phase boundary turns out to depend quite sensitively on the driving amplitude. A more quantitative analysis shows even that the effect of driving can be described within the usual Bose-Hubbard model provided that the hopping is rescaled appropriately with the driving amplitude. This finding indicates that the Bose-Hubbard model with a periodically driven s-wave scattering length and the usual Bose-Hubbard model belong to the same universality class from the point of view of critical phenomena.
[1] A. Rapp, X. Deng, and L. Santos, Phys. Rev. Lett. 109, 203005 (2012).