Hannover 2020 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 22: Posters: Quantum Optics and Photonics II

Q 22.53: Poster

Tuesday, March 10, 2020, 16:30–18:30, Empore Lichthof

Floquet engineering of strongly correlated fermions in optical lattices — •Kilian Sandholzer, Joaquín Minguzzi, Anne-Sophie Walter, Konrad Viebahn, Frederik Görg, and Tilman Esslinger — ETH Zürich, Switzerland

The successful implementation of Floquet engineering in the field of cold atoms has enabled the study of Hamiltonians which would be out of reach in static systems. However, introducing strong interactions to these systems makes them susceptible to absorbing energy from the external drive which prevents the buildup of strong correlations.

We use an interaction-tunable Fermi gas in a periodically modulated hexagonal lattice to realize the driven Fermi-Hubbard model. In the static analog, for low temperatures nearest-neighbor spin correlations develop as a consequence of the interplay between particle hopping and onsite interactions. By driving the system close to the interaction energy, we can either enhance antiferromagnetic or induce ferromagnetic correlations. In the case of a two-frequency scheme, we demonstrate the implementation of an occupation-dependent gauge field. For these systems, a study of the evolution of doubly occupied sites shows that the heating due to the drive is not limiting the investigation of low-energy physics. In comparison to dynamical mean field theory we verify the validity of the experiments and theoretical calculations. Furthermore, we can show that the lifetime of spin correlations in a driven system can be made identical to the static system by applying coherent control to avoid heating into higher bands.