arXiv:cond-mat/0412638 · Physical Review B
Static properties of the dissipative random quantum Ising ferromagnetic chain
Leticia F. Cugliandolo, Gustavo Sergio Lozano, H. Lozza
Abstract
We study the zero-temperature static properties of dissipative ensembles of quantum Ising spins arranged on periodic one-dimensional finite clusters and on an infinite chain. The spins interact ferro-magnetically with nearest-neighbor pure and random couplings. They are subject to a transverse field and coupled to an Ohmic bath of quantum harmonic oscillators. We analyze the coupled system using Monte Carlo simulations of the classical two-dimensional counterpart model. The coupling to the bath enhances the extent of the ordered phase, as found in mean-field spin glasses. In the case of finite clusters, we show that a generalization of the Caldeira-Leggett localization transition exists. In the case of the infinite random chain, we study the effect of dissipation on the transition and the Griffiths phase.