English

Topological pumping in a Floquet-Bloch band

Quantum Gases 2022-11-09 v2 Mesoscale and Nanoscale Physics Atomic Physics Optics

Abstract

Constructing new topological materials is of vital interest for the development of robust quantum applications. However, engineering such materials often causes technological overhead, such as large magnetic fields, specific lattice geometries, strong spin-orbit coupling, synthetic dimensions, or dynamical superlattice potentials. Simplifying the experimental requirements has been addressed on a conceptual level - by proposing to combine simple lattice structures with Floquet engineering - but there has been no experimental implementation. Here, we demonstrate topological pumping in a Floquet-Bloch band using a plain sinusoidal lattice potential and two-tone driving with frequencies ω\omega and 2ω2\omega. We adiabatically prepare a near-insulating Floquet band of ultracold fermions via a frequency chirp, which avoids gap closings en route from trivial to topological bands. Subsequently, we induce topological pumping by slowly cycling the amplitude and the phase of the 2ω2 \omega drive. Our system is well described by an effective Shockley model, establishing a novel paradigm to engineer topological matter from simple underlying lattice geometries. This approach could enable the application of quantised pumping in metrology, following recent experimental advances on two-frequency driving in real materials.

Keywords

Cite

@article{arxiv.2112.12788,
  title  = {Topological pumping in a Floquet-Bloch band},
  author = {Joaquín Minguzzi and Zijie Zhu and Kilian Sandholzer and Anne-Sophie Walter and Konrad Viebahn and Tilman Esslinger},
  journal= {arXiv preprint arXiv:2112.12788},
  year   = {2022}
}

Comments

13 pages, 11 figures