Glassy dynamics of the one-dimensional Mott insulator excited by a strong terahertz pulse

TL;DR

This paper studies how strong terahertz pulses induce a glassy, insulator-to-metal transition in a one-dimensional Mott insulator, revealing suppression of conductivity due to Hilbert-space fragmentation.

Contribution

It demonstrates that quantum tunneling under strong pulses causes spectral weight suppression and glassy states, contrasting with conventional metallic behavior.

Findings

Strong pulses suppress Drude weight despite increased carriers

Quantum tunneling leads to Hilbert-space fragmentation and glassy states

Pulse-induced states differ from doping-induced metallic states

Abstract

The elucidation of nonequilibrium states in strongly correlated systems holds the key to emergence of novel quantum phases. The nonequilibrium-induced insulator-to-metal transition is particularly interesting since it reflects the fundamental nature of competition between itinerancy and localization of the charge degrees of freedom. We investigate pulse-excited insulator-to-metal transition of the half-filled one-dimensional extended Hubbard model. Calculating the time-dependent optical conductivity with the time-dependent density-matrix renormalization group, we find that strong mono- and half-cycle pulses inducing quantum tunneling strongly suppress spectral weights contributing to the Drude weight $\sigma_\text{D}$, even if we introduce a large number of carriers $\Delta n_\text{d}$. This is in contrast to a metallic behavior of $\sigma_\text{D}\propto \Delta n_\text{d}$ induced by photon absorption and chemical doping. The strong suppression of $\sigma_\text{D}$ in quantum tunneling is a result of the emergence of the Hilbert-space fragmentation, which makes pulse-excited states glassy.