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Topological pump of ultracold fermions in a one dimensional shaken optical lattice

ORAL

Abstract

Topological pumps allow quantized transport of particles in periodic potentials, in which external parameters are varied in a slow, cyclic manner. Their topological origin is analogous to the quantum Hall effect, in that the amount of transported charge is robust against perturbations and does not depend on the specific pumping protocol. In atomic physics, ultracold atoms in optical lattices are versatile systems to observe such topological effects. So far, charge pumping has been achieved in dynamically controlled bipartite optical lattices, which operate in a regime where atoms adiabatically follow the cyclically deformed lattice potential. Here, we experimentally realize a topological pump of ultracold spin-polarized fermions in a simple one dimensional optical lattice. The experiment consists in resonantly shaking an optical lattice to prepare the fermions in a hybridized orbital, which endows the atomic cloud with a non-centrosymmetric charge polarization. Pumping is subsequently achieved by periodically modulating the shaking waveform slow enough to ensure adiabaticity. In contrast to previous experiments, which have been based on the Rice-Mele model, our measurements are consistent with the fully connected Creutz-ladder Hamiltonian. These results pave the way for studying topological pumping in the interacting regime.

Presenters

  • Joaquin Minguzzi

    ETH Zurich

Authors

  • Joaquin Minguzzi

    ETH Zurich

  • Kilian Sandholzer

    ETH Zurich

  • Anne-Sophie Walter

    ETH Zurich

  • Zijie Zhu

    ETH Zurich

  • Konrad G Viebahn

    ETH Zurich

  • Tilman Esslinger

    ETH Zurich, Institute for Quantum Electronics, ETH Zürich, Department of Physics, ETH Zurich, 8093 Zurich, Switzerland