Absorbing phase transition with a continuously varying exponent in a quantum contact process: A neural network approach

Abstract

Phase transitions in dissipative quantum systems are intriguing because they are induced by the interplay between coherent quantum and incoherent classical fluctuations. Here, we investigate the crossover from a quantum to a classical absorbing phase transition arising in the quantum contact process (QCP). The Lindblad equation contains two parameters, ω and κ, which adjust the contributions of the quantum and classical effects, respectively. We find that in one dimension, when the QCP starts from a homogeneous state with all active sites, there exists a critical line in the region 0≤κ