Topological pumping in a Floquet-Bloch band

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 $\omega$ and $2\omega$. 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 $2\omega$ 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.

13 pages, 11 figures

References in corpus (10)

• Tunable gauge potential for neutral and spinless particles in driven lattices
• Tailoring quantum gases by Floquet engineering
• Quantized Nonlinear Thouless Pumping
• Measuring a topological transition in an artificial spin 1/2 system
• Shaping topological properties of the band structures in a shaken optical lattice
• Suppressing dissipation in a Floquet-Hubbard system
• Floquet engineering of individual band gaps in an optical lattice using a two-tone drive
• Orbital embedding and topology of one-dimensional two-band insulators
• Excitation of atoms in an optical lattice driven by polychromatic amplitude modulation
• Topological Floquet engineering of a 1D optical lattice via resonantly shaking with two harmonic frequencies

Cited by in corpus (7)

• Thouless pumping and topology
• Quantisation and its breakdown in a Hubbard-Thouless pump
• Quantized Topological Anderson-Thouless Pump
• Reversal of quantised Hall drifts at non-interacting and interacting topological boundaries
• Topological phase transition in commensurate multi-frequency Floquet Su-Schrieffer-Heeger model
• Topological dynamics of adiabatic cat states
• Suppression of scattering from slow to fast subsystems and application to resonantly Floquet-driven impurities in strongly interacting systems