Controlling and characterizing Floquet prethermalization in a driven quantum system
Kevin Singh, Kurt Fujiwara, Zachary A. Geiger, Ethan Q. Simmons, Mikhail Lipatov, Alec Cao, Peter Dotti, S. Rajagopal, Ruwan Senaratne, Toshihiko Shimasaki, Markus Heyl, André Eckardt, David Weld · arXiv (Cornell University) · 2018
Periodic driving is a powerful tool for engineering tunable many-body quantum states. Such Floquet engineering relies on the existence of a localized prethermal regime, a state which remains incompletely understood. We report experiments on a many-body Floquet system consisting of ultracold atoms in an optical lattice subjected to sign-changing amplitude modulation. A double-quench protocol enables measurement of an inverse participation ratio quantifying the degree of prethermal localization as a function of continuously tunable drive parameters and interactions. Following the time evolution of the driven system, we observe the sequential formation of two localized prethermal plateaux, interaction-driven delocalization, and strongly frequency-dependent dynamics of departure from the prethermal state. The experimental control and quantitative characterization of Floquet prethermalization opens new possibilities for dynamical quantum engineering.