Dynamical localization of interacting ultracold atoms in one-dimensional quasi-periodic potentials

Abstract

We present numerically exact non-equilibrium dynamics of a one-dimensional Bose gas in quasi-periodic lattice that plays an intermediate role between the long-ranged order and truly disordered systems exhibiting unusual correlated phases. Precision control over lattice depth, interaction strength and filling factor enables the exploration of various correlated phases in a finite periodic lattice. We investigate the system dynamics when the secondary incommensurate lattice is abruptly switched on. To solve the many-body Schroedinger equation, we employ the multiconfigurational time-dependent Hartree method for bosons (MCTDHB). The many-body dynamics are analyzed through distinct measures of the Glauber correlation functions and dynamical fragmentation. Our study reveals four distinct scenarios of localization process in the non-equilibrium dynamics. Weakly interacting non-fragmented superfluid of incommensurate filling in the primary lattice exhibits collapse-revival dynamics of localization. In contrast, a fragmented superfluid with commensurate filling exhibits dynamical Mott localization. A strongly correlated, fully fragmented Mott state shows a subtle competition with localization introduced by the secondary lattice that merely melts the Mott correlations. Interestingly, in the fermionized Mott regime, where the density in each well is fragmented, the intra-dimer correlations exhibit unexpected robustness. These findings provide new insights into many-body correlation dynamics and novel localization mechanisms in quasi-periodic lattices, paving the way for engineering exotic quantum behaviors in ultracold atomic systems.