Quenching the Anisotropic Heisenberg Chain: Exact Solution and   Generalized Gibbs Ensemble Predictions
  We study quenches in integrable spin-1/2 chains in which we evolve the ground state of the antiferromagnetic Ising model with the anisotropic Heisenberg Hamiltonian. For this nontrivially interacting situation, an application of the first-principles-based quench action method allows us to give an exact description of the postquench steady state in the thermodynamic limit. We show that a generalized Gibbs ensemble, implemented using all known local conserved charges, fails to reproduce the exact quench action steady state and to correctly predict postquench equilibrium expectation values of physical observables. This is supported by numerical linked-cluster calculations within the diagonal ensemble in the thermodynamic limit. 
Bram Wouters, Jacopo De Nardis, Michael Brockmann, Davide Fioretto,   Marcos Rigol and Jean-S\'ebastien Caux
cond-mat.str-el cond-mat.stat-mech