Paper detail

Entanglement entropy of disordered quantum chains following a global quench

We numerically investigate the growth of the entanglement entropy S_{ent}(t) in time t---after a global quench from a product state---in quantum chains with various kinds of disorder. The main focus is, in particular, on fermionic chains with bond disorder. In the noninteracting case at criticality we numerically test recent predictions by the real space renormalization group for the entanglement growth in time, the maximal entanglement as a function of block size, and the decay of a density wave order parameter. We show that multiprecision calculations are required to reach the scaling regime and perform such calculations for specific cases. For interacting models with binary bond disorder we present data based on infinite size density matrix renormalization group calculations and exact diagonalizations. We obtain first numerical evidence for a many-body localized phase in bond disordered systems where S_{ent}(t)~ln t$ seems to hold. Our results for bond disorder are contrasted with the well studied case of potential disorder.