Correlations after quantum quenches in the XXZ spin chain: Failure of the Generalized Gibbs Ensemble

Understand

We study the nonequilibrium time evolution of the spin-1/2 anisotropic Heisenberg (XXZ) spin chain, with a choice of dimer product and Neel states as initial states.

• We investigate numerically various short-ranged spin correlators in the long-time limit and find that they deviate significantly from predictions based on the generalized Gibbs ensemble (GGE) hypotheses.
• By computing the asymptotic spin correlators within the recently proposed quench-action formalism [Phys.
• Rev.