By means of free fermionic techniques we study the time evolution of the entanglement entropy S(t) of a block of spins in the random transverse-field Ising chain after a sudden change of the parameters of the Hamiltonian. We consider global quenches, when the parameters are modified uniformly in space, as well as local quenches, when two disconnected blocks are suddenly joined together. For a noncritical final state, the dynamical entanglement entropy is found to approach a finite limiting value for both types of quenches. If the quench is performed to the critical state, the entropy grows for an infinite block as S(t)∼lnlnt. This type of ultraslow increase is explained through the strong disorder renormalization group method.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - Mar 12 2012|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics