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Q: Fachverband Quantenoptik und Photonik

Q 42: Poster: Quantum Optics and Photonics II

Q 42.31: Poster

Mittwoch, 13. März 2019, 16:15–18:15, S Atrium Informatik

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

Periodic driving has proven very powerful in realising paradigmatic hamiltonians with ultracold atoms. Examples include the topological Haldane model, and the control over the magnitude and sign of magnetic correlations in a Fermi-Hubbard system. However, the validity of the Floquet description in the many-body context is not yet fully understood. Long evolution times pose a natural limit as the system will inevitably heat to infinity due to interactions which break ergodicity. It is therefore crucial to identify relevant timescales on which the effective (static) Floquet hamiltonian remains valid. In this experiment we study the dynamics and timescales of a periodically driven Fermi-Hubbard model in a three-dimensional hexagonal lattice. The evolution of the Floquet many-body state is analysed and compared to an equivalent undriven system. The dynamics of double occupancies for the near- and off-resonant driving regime indicate that the effective Hamiltonian picture is valid for several orders of magnitude in modulation time. Furthermore, we identify a strong dependence of the heating performance on the lattice geometry. A hexagonal-type lattice proves particularly advantageous, even when driving at resonance with the interaction energy, allowing for modulations times of up to ∼1 s, which corresponds to hundreds of tunnelling times.