Controlling the Floquet state population and observing micromotion in a periodically driven two-body quantum system

Research paper by Rémi Desbuquois, Michael Messer, Frederik Görg, Kilian Sandholzer, Gregor Jotzu, Tilman Esslinger

Indexed on: 22 Mar '17Published on: 22 Mar '17Published in: arXiv - Condensed Matter - Quantum Gases


Near-resonant periodic driving of quantum systems promises the implementation of a large variety of novel effective Hamiltonians. The challenge of Floquet engineering lies in the preparation and measurement of the desired quantum state. We address these aspects in a model system consisting of interacting fermions in a periodically driven array of double wells created by an optical lattice. The singlet and triplet fractions and the double occupancy of the Floquet states are measured, and their behavior as a function of the interaction strength is analyzed in the high- and low-frequency regimes. We demonstrate full control of the Floquet state population and find suitable ramping protocols and time-scales which adiabatically connect the initial ground state to different targeted Floquet states. The micromotion which exactly describes the time evolution of the system within one driving cycle is observed. Additionally, we provide an analytic description of the model and compare it to numerical simulations.