Critical behavior of dissipative two-dimensional spin lattices

TL;DR

This paper investigates the critical phenomena in two-dimensional dissipative spin lattices, revealing how quantum correlations and entropy behave across a ferromagnetic phase transition in a non-equilibrium setting.

Contribution

It introduces a novel analysis of dissipative 2D spin systems using the corner-space renormalization method and characterizes the critical behavior of quantum correlations and entropy.

Findings

Von Neumann entropy increases at the critical point

Quantum Fisher information shows critical behavior

Finite-size scaling of magnetic susceptibility

Abstract

We explore critical properties of two-dimensional lattices of spins interacting via an anisotropic Heisenberg Hamiltonian and subject to incoherent spin flips. We determine the steady-state solution of the master equation for the density matrix via the corner-space renormalization method. We investigate the finite-size scaling and critical exponent of the magnetic linear susceptibility associated to a dissipative ferromagnetic transition. We show that the Von Neumann entropy increases across the critical point, revealing a strongly mixed character of the ferromagnetic phase. Entanglement is witnessed by the quantum Fisher information which exhibits a critical behavior at the transition point, showing that quantum correlations play a crucial role in the transition even though the system is in a mixed state.