arXiv:cond-mat/9609185 · Physical Review Letters
Low Temperature Relaxational Dynamics of the Ising Chain in a Transverse Field
Subir Sachdev A, A. P. Young
Abstract
We present asymptotically exact results for the real time order parameter correlations of a class of $d\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1$ Ising models in a transverse field at low temperatures ( $T$) on both sides of the quantum critical point. The correlations are a product of a $T$-independent factor determined by quantum effects, and a $T$-dependent relaxation function which comes from a classical theory. We confirm our predictions by a no-free-parameter comparison with numerical studies on the nearest neighbor spin-1/2 model.