International Journal of Modern Physics B
ZERO-TEMPERATURE PHASE DIAGRAM OF DISSIPATIVE RANDOM ISING FERROMAGNETIC CHAINS
Leticia F. Cugliandolo, Gustavo Sergio Lozano, H. Lozza
Abstract
We study the zero-temperature critical behavior of dissipative quantum Ising spin chains of finite and infinite length. The spins interact with either constant or random nearest-neighbor ferro-magnetic couplings. They are also subject to a transverse field and coupled to an Ohmic bath of quantum harmonic oscillators. We analyze the coupled system performing Monte Carlo simulations on a classical two-dimensional counterpart model. We find that the coupling to the bath enhances the extent of the ordered phase, as it is known for mean-field spin-glass models. In the case of finite chains we show that a generalization of the Caldeira-Leggett localization transition exists.