Quantum quenches in a spin-1 chain with tunable symmetry

TL;DR

This paper investigates the non-equilibrium dynamics of a tunable spin-1 Heisenberg chain using TEBD, revealing a conserved quantity at SU(3) symmetry and connecting theoretical insights with experimental platforms.

Contribution

It introduces a tunable model interpolating between non-integrable and integrable regimes and identifies a new conserved quantity at SU(3) symmetry.

Findings

Identification of a new conserved quantity at the SU(3) symmetric point.

Numerical analysis of magnetization, entanglement, and correlations across the tunable parameter.

Theoretical explanation of numerical results based on conservation laws.

Abstract

In recent years, the dynamics of interacting quantum systems far from equilibrium have attracted significant research interest. Driven by rapid progress in quantum simulators, various non-equilibrium phenomena have now been realized experimentally. In this work, we use the time-evolving block decimation (TEBD) method to investigate the dynamics of an anisotropic spin-1 Heisenberg chain for a wide range of experimentally accessible initial states. By adjusting the parameter $J_q$ that controls the quadrupolar interaction strength, we can tune the system from a non-integrable SU(2) Heisenberg model to an integrable SU(3) Heisenberg model. We examine the local magnetization, entanglement entropy, and spin correlations, and characterize their dependence on $J_q$. We identify a new conserved quantity at the SU(3) symmetric point and provide a theoretical framework to explain our numerical observations in terms of the number of accessible states permitted by this conservation law. Our results provide a route to realize a rich array of non-equilibrium behavior in spin-1 lattice models, which can be engineered in several experimental platforms such as ultracold atoms in optical lattices.