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.
Highlights
The nonequilibrium dynamics of quantum many-body systems is a vibrant field of research, much less well understood than the phases of matter in thermal equilibrium
In this paper we have analyzed the dynamics of the extended Bose-Hubbard model after sudden interaction quenches
These dynamical quantum phase transitions (DQPTs) bear no correspondence to the equilibrium phase boundaries and no relation to topology
Summary
The nonequilibrium dynamics of quantum many-body systems is a vibrant field of research, much less well understood than the phases of matter in thermal equilibrium. The link of DQPTs with order parameter dynamics and equilibrium phase transitions is much more ambiguous for nonintegrable models [45,46,47,48] Recently, such correspondences were found for quenches in a nonintegrable spin-1 XXZ chain, with respect to the symmetry protected topological Haldane phase and its nonlocal string order parameter [49,50]. Such a model has been experimentally realized [51,52]. We show that the time of the first DQPTs depends on the quench parameter roughly in a power law fashion for both kinds of initial states, while the detailed forms differ between the interaction-driven and topological cases
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