Seminar
Tuesday, 09 February, 2010
Group seminar MPQ: High-energy excitations, dynamics and thermometry of ultracold Fermions in an optical lattice
Tuesday, 09.02.2010 10 a.m. (s.t.) in Herbert-Walther-lecture room, MPQ Garching
Robert Jördens, Quantum Optics Group, Institute for Quantum Electronics, ETH Zürich
I will present the results of a combined experimental and numerical study of repulsively interacting fermionic atoms in the Hubbard model. The double occupancy provides direct access to the system's properties both in equilibrium and in the linear response regime. We determine the entropy in the lattice above the transition to magnetic order and demonstrate the applicability of both high-temperature series and dynamical mean field theory in this regime. The time resolved build-up of double occupancy during tunneling modulation exhibits a linear response that is sensitive to density and temperature and can be used to detect local spin ordering.