Rostock 2019 – wissenschaftliches Programm

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Q: Fachverband Quantenoptik und Photonik

Q 12: Quantum Gases (Bosons and Fermions) I

Q 12.2: Vortrag

Montag, 11. März 2019, 14:15–14:30, S HS 037 Informatik

Floquet dynamics in driven Fermi-Hubbard systems — •Joaquín Minguzzi, Michael Messer, Kilian Sandholzer, Frederik Görg, Konrad Viebahn, Rémi Desbuquois, and Tilman Esslinger — Institute for Quantum Electronics, ETH Zurich, CH-8093 Zurich

Floquet engineering is a widely applicable method to realize novel effectively static Hamiltonians via driving a quantum system. Several experiments have successfully demonstrated Floquet Hamiltonians in non-interacting ultracold atoms. Yet, the time scales were this effective Hamiltonian is appropiate to describe the dynamics of a driven strongly-interacting many-body state have not been explored. In particular, the system is expected to heat up due to continuous energy absorption from the drive. We experimentally study these aspects in the driven Fermi-Hubbard model using strongly-interacting ultracold fermions in a driven three-dimensional optical lattice. The dynamics of the engineered Floquet state is compared to the one of an equivalent static many-body state. Our observables show that these dynamics coincide up to several hundreds of driving cycles, validating the applicability of the Floquet Hamiltonian. This time scale is ultimately limited by Floquet heating and consequently atom loss, which is mitigated in a lattice with hexagonal geometry. Large bandgaps and less dispersive bands broaden the frequency window suitable for driving with suppresed atom loss. Our results establish that the driven Fermi-Hubbard model can be implemented on realistic experimental time scales and in future work could be benchmarked with theoretical methods.