Universal dynamics of a soliton after an interaction quench

TL;DR

This paper investigates the universal short-time dynamics of solitons after an interaction quench across various quantum systems, revealing that these dynamics are largely independent of microscopic details and robust to integrability breaking.

Contribution

It introduces a new quantum quench protocol involving a soliton, and demonstrates the universality of the resulting short-time dynamics using hydrodynamic theory and numerical simulations.

Findings

Short-time soliton dynamics are universal across different models.

Numerical simulations support the universality in non-linear Schrödinger and Calogero models.

Universality persists despite integrability breaking by external potentials and non-linearities.

Abstract

We propose a new type of experimentally feasible quantum quench protocol in which a quantum system is prepared in a coherent, localized excited state of a Hamiltonian. During the evolution of this solitonic excitation, the microscopic interaction is suddenly changed. We study the dynamics of solitons after this interaction quench for a wide class of systems using a hydrodynamic approach. We find that the post-quench dynamics is universal at short times, i.e. it does not depend on the microscopic details of the physical system. Numerical support for these results is presented using generalized non-linear Schroedinger equation, relevant for the implementation of the proposed protocol with ultracold bosons, as well as for the integrable Calogero model in harmonic potential. Finally, it is shown that the effects of integrability breaking by a parabolic potential and by a power-law non-linearity do not change the universality of the short-time dynamics.