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

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(D), even if we introduce a large number of carriers Delta n(d). This is in contrast to a metallic behavior of sigma(D) proportional to Delta n(d) induced by photon absorption and chemical doping. The strong suppression of a D in quantum tunneling is a result of the emergence of the Hilbert-space fragmentation, which makes pulse-excited states glassy.