Quantum spin chains with site dissipation

TL;DR

This paper investigates quantum spin chains with site dissipation using Monte Carlo simulations, revealing phase diagrams and critical exponents that align with theoretical predictions, and extends analysis to XY-chains with second order phase transitions.

Contribution

It provides the first detailed Monte Carlo study of dissipative XY spin chains, including phase diagrams and critical exponents, and compares results with dissipative field theory.

Findings

Phase diagram of dissipative XY-chain identified.

Critical exponents match theoretical predictions.

Universal susceptibility ratio computed for dissipative Ising chain.

Abstract

We use Monte Carlo simulations to study chains of Ising- and XY-spins with dissipation coupling to the site variables. The phase diagram and critical exponents of the dissipative Ising chain in a transverse magnetic field have been computed previously, and here we consider a universal ratio of susceptibilities. We furthermore present the phase diagram and exponents of the dissipative XY-chain, which exhibits a second order phase transition. All our results compare well with the predictions from a dissipative $\phi^4$ field theory.