QUROPE Quantum Information Processing and Communication in Europe

We investigate the equilibration dynamics of non-local order in a one-dimensional quantum system. After initializing a spin-1 chain in the Haldane phase, the time evolution of string correlations following a sudden quench is studied by means of matrix-product-state-based algorithms. Thermalization occurs only for scales up to a horizon which grows at a well defined speed, due to the finite maximal velocity at which string correlations can propagate, related to a Lieb-Robinson bound. The persistence of string ordering at finite times is related to the symmetries of the quenched Hamiltonian in a non-trivial way. Our results are suitable to experimental testing in present cold-atom setups.