Heidelberg 2015 – wissenschaftliches Programm
Q 32.5: Poster
Dienstag, 24. März 2015, 17:00–19:00, C/Foyer
Positive and negative quenches induced excitation dynamics for ultracold bosons in one-dimensional lattices — •Simeon Mistakidis1, Lushuai Cao1,2, and Peter Schmelcher1,2 — 1Zentrum für Optische Quantentechnologien, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany — 2The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
The correlated non-equilibrium dynamics of few-boson systems in one-dimensional finite lattices is investigated. Focusing on the low-lying modes of the finite lattice we observe the emergence of density-wave tunneling, breathing and cradle-like processes. In particular, the tunneling induced by the quench leads to a global density-wave oscillation. The resulting breathing and cradle modes are inherent to the local intrawell dynamics and related to excited-band states. Positive interaction quenches couple the density-wave and the cradle modes allowing for resonance phenomena. Moreover, the cradle mode is associated with the initial delocalization and following a negative interaction quench can be excited for incommensurate setups with filling larger than unity. For subunit and commensurate fillings it can be accessed with the aid of a negative quench of the optical lattice depth. Finally, our results shed light to possible controlling schemes for the cradle and the breathing modes in terms of the tunable parameters of the Hamiltonian. The evolution of the system is obtained numerically using the ab-initio multi-layer multi-configuration time-dependent Hartree method for bosons.