Transport in Floquet-Bloch bands

TL;DR

This paper demonstrates Floquet band engineering in an optical lattice, enabling tunable long-range transport and direct imaging of Floquet-Bloch bands, which advances quantum emulation of ultrafast electronic dynamics.

Contribution

It introduces a method to engineer Floquet-Bloch bands in optical lattices and directly image their structure through transport dynamics.

Findings

Observation of tunable long-range high-fidelity transport across thousands of sites

Controlled switching between transport and localization using band hybridization

Direct imaging of Floquet-Bloch band structure via transport measurements

Abstract

We report Floquet band engineering of long-range transport and direct imaging of Floquet-Bloch bands in an amplitude-modulated optical lattice. In one variety of Floquet-Bloch band we observe tunable rapid long-range high-fidelity transport of a Bose condensate across thousands of lattice sites. Quenching into an opposite-parity Floquet-hybridized band allows Wannier-Stark localization to be controllably turned on and off using modulation. A central result of this work is the use of transport dynamics to demonstrate direct imaging of a Floquet-Bloch band structure. These results demonstrate that transport in dynamical Floquet-Bloch bands can be mapped to transport in quasi-static effective bands, opening a path to cold atom quantum emulation of ultrafast multi-band electronic dynamics.