Floquet prethermalization and Rabi oscillations in optically excited Hubbard clusters

Abstract

We study the properties of Floquet prethermal states in two-dimensional Mott-insulating Hubbard clusters under continuous optical excitation. With exact-diagonalization simulations, we show that Floquet prethermal states emerge not only off resonance, but also for resonant excitation, provided a small field amplitude. In the resonant case, the long-lived quasi-stationary Floquet states are characterized by Rabi oscillations of observables such as double occupation and kinetic energy. At stronger fields, thermalization to infinite temperature is observed. We provide explanations to these results by means of time-dependent perturbation theory. The main findings are substantiated by a finite-size analysis.

Photoinduced intradomain dynamics and nonthermal switching of metastable states in the one-dimensional extended Peierls-Hubbard model

“…This is because the different optical pulses change only the weights of a few excited states but not the set of the states. This may be connected to the spin-charge separation, which allows only the discrete number of excited states [75], and possible localization in the energy eigenstates [79].…”

“…As the pulse becomes stronger or shorter [case (ii)], the system shows a photoinduced transition to a metastable state. As the pump pulse becomes too strong [case (iii)], the system is heated up to be the infinite-temperature state [79]; there is no electronic order, and the double occupation density l n l↑ n l↓ /L approaches to 1/4. These three regimes (i)-(iii) are labeled in Fig.…”