Interaction-driven dynamical quantum phase transitions in a strongly correlated bosonic system

TL;DR

This paper investigates dynamical quantum phase transitions in a strongly correlated bosonic system after a sudden change in interaction strength, revealing new phenomena in topologically trivial phases and introducing novel order parameters.

Contribution

It demonstrates the occurrence of interaction-driven DQPTs between trivial insulating phases and introduces new string and parity order parameters to analyze these transitions.

Findings

Interaction-driven DQPTs occur at a threshold interaction strength.

New string and parity order parameters are closely linked to DQPTs.

Distinct power-law behaviors are observed for different types of DQPTs.

Abstract

We study dynamical quantum phase transitions (DQPTs) in the extended Bose-Hubbard model after a sudden quench of the nearest-neighbor interaction strength. Using the time-dependent density matrix renormalization group, we demonstrate that interaction-driven DQPTs can appear after quenches between two topologically trivial insulating phases -- a phenomenon that has so far only been studied between gapped and gapless phases. These DQPTs occur when the interaction strength crosses a certain threshold value that does not coincide with the equilibrium phase boundaries, which is in contrast to quenches that involve a change of topology. In order to elucidate the nonequilibrium excitations during the time evolution, we define a new set of string and parity order parameters. We find a close connection between DQPTs and these newly defined order parameters for both types of quenches. In the interaction-driven case, the order parameter exhibits a singularity at the time of the DQPT only when the quench parameter is close to the threshold value. Finally, the timescales of DQPTs are scrutinized and different kinds of power laws are revealed for the topological and interaction-driven cases.