Dr. Matthew S. Foster

Department of Physics and Astronomy

Rutgers, the State University of New Jersey

Quantum quench in 1D: Fractionalization and "supersolitons"

Abstract:

The non-equilibrium dynamics of a many-body system following a sudden deformation of the system Hamiltonian (a "quantum quench") has recently attracted much interest following rapid experimental progress in the field of cold atoms. A particularly fascinating setup involves the quench across a zero temperature quantum phase boundary separating gapless (critical) and gapped ground states. Here, we consider the dynamics of localized excitations produced following a quench in the 1D quantum sine Gordon model, with Luttinger liquid and Mott insulating ground states favored by the pre- and post-quench Hamiltonians, respectively. Due to quasiparticle fractionalization (a ubiquitous feature in 1D), the quench is found to induce the production of relativistic, non-dispersive, traveling density waves, which we dub "supersolitons." We show that the supersolitons do not interact, and we discuss the prospects for their observation in a lattice system.