Semiclassical Approach to Survival Probability at Quantum Phase Transitions

Wen-ge Wang, Pinquan Qin, Lewei He, Ping Wang

Published 2009-07-22, updated 2010-02-02Version 3

We study the decay of survival probability at quantum phase transitions (QPT). The semiclassical theory is found applicable in the vicinities of critical points with infinite degeneracy. The theory predicts a power law decay of the survival probability for relatively long times in systems with d=1 and an exponential decay in systems with sufficiently large d, where d is the degrees of freedom of the underlying classical dynamics. The semiclassical predictions are checked numerically in four models.