Hannover 2013 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 7: Ultra-cold atoms, ions and BEC I (with A)
Q 7.2: Talk
Monday, March 18, 2013, 11:30–11:45, B 305
Interaction induced modification of tunnelling rates in a 1D tilted optical lattice — •Florian Meinert1, Manfred Mark1, Emil Kirilov1, Katharina Lauber1, Philipp Weinmann1, Andrew Daley2, and Hanns-Christoph Nägerl1 — 1Institut für Experimentalphysik, Universität Innsbruck — 2Physics and Astronomy, University of Pittsburgh
Cold atoms confined in optical lattice potentials offer unique access to study condensed matter Hamiltonians, e.g. the bosonic Hubbard model. Magnetic Feshbach resonances provide high control and tunability of the interparticle on-site interaction strength allowing for the preparation of Mott insulating phases with both, attractive and repulsive interaction.
We study correlated tunnelling dynamics of degenerate bosonic Cs atoms prepared in one dimensional singly occupied Mott insulating chains. Subjecting the atoms to a linear potential gradient that is adiabatically ramped through resonance with the interaction energy results in a doublon-hole density wave order, a situation that maps onto the quantum phase transition from the paramagnetic to the anti-ferromagnetic state in the 1D transverse Ising model.
By quenching the system onto the phase transition point we initiate non-equilibrium tunnelling dynamics as detected in the number of created doubly occupied lattice sites. The observed coherent response of the system provides a direct measure of the tunnelling rate. We observe striking modification of this rate by interactions when tuned from attractive to repulsive.