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Abstract
In this work, we study complex many-body systems consisting of ultracold bosonic atoms in optical lattices.Motivated by the state-of-the-art of experiments realizing higher bands physics with ultracold atoms, we use a one-dimensional bichromatic optical lattice, whose properties permit to engineer a very well isolated two-band system. The underlying single- and manyparticle physics is investigated based on a two-band Bose-Hubbard Hamiltonian. An external Stark force is introduced to drive the inter-band dynamics. In a first, andmain part of thiswork, we numerically characterize ourmany-bodyWannier-Stark systemthrough its spectral and dynamical properties, in terms of important system parameters. We present a detailed study of the diffusion in Hilbert space. Relaxation and controlled non-adiabatic dynamics are studied by driving the system across the spectral resonances, mainly by using quantum sweeps. In a second part, we implement an effective Hamiltonian in order to characterize the spectral properties of a leaky one-dimensional optical lattice with controlled dissipation. We show that the stability of long-lived localizedmany-body states, i.e. discrete solitonic states, can be described with good accuracy by the decay rates statistics of the accessible complex energy spectrum of the effective (non-hermitian)Hamiltonian.
Document type: | Dissertation |
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Supervisor: | Wimberger, PD Dr. Sandro |
Place of Publication: | Heidelberg |
Date of thesis defense: | 29 May 2013 |
Date Deposited: | 26 Jun 2013 09:24 |
Date: | 2013 |
Faculties / Institutes: | The Faculty of Physics and Astronomy > Institute for Theoretical Physics |
DDC-classification: | 530 Physics |
Controlled Keywords: | Wannier-Stark System, Quantum Chaos, Many-Body Dynamics |
Uncontrolled Keywords: | Wannier-Stark, Optical lattices, Quantum Chaos, Many-Body Dynamics |