Entanglement entropy dynamics of Heisenberg chains

Abstract

By means of the time-dependent density matrix renormalization group algorithm\nwe study the zero-temperature dynamics of the Von Neumann entropy of a block of\nspins in a Heisenberg chain after a sudden quench in the anisotropy parameter.\nIn the absence of any disorder the block entropy increases linearly with time\nand then saturates. We analyze the velocity of propagation of the entanglement\nas a function of the initial and final anisotropies and compare, wherever\npossible, our results with those obtained by means of Conformal Field Theory.\nIn the disordered case we find a slower (logarithmic) evolution which may\nsignals the onset of entanglement localization.\n