Tuning entanglement and ergodicity in two-dimensional spin systems using impurities and anisotropy

TL;DR

This study explores how impurities and anisotropy influence entanglement and ergodicity in a two-dimensional XY spin system, revealing controllable quantum properties and phase transition behaviors.

Contribution

It introduces the analysis of impurity effects and anisotropy on entanglement and ergodicity in a 2D spin system, extending understanding beyond 1D models.

Findings

Entanglement mimics 1D systems at extreme h/J values.

Phase transition occurs near h/J=2 for anisotropic systems.

Impurities can control ergodicity of the system.

Abstract

We consider the entanglement in a two dimensional XY model in an external magnetic field h. The model consists of a set of 7 localized spin-1/2 particles in a two dimensional triangular lattice coupled through nearest neighbor exchange interaction J. We examine the effect of single and double impurities in the system as well as the degree of anisotropy on the nearest neighbor entanglement and ergodicity of the system. We have found that the entanglement of the system at the different degrees of anisotropy mimics that of the one dimensional spin systems at the extremely small and large values of the parameter h/J. The entanglement of the Ising and partially anisotropic system show phase transition in the vicinity of h/J = 2 while the entanglement of the isotropic system suddenly vanishes there. Also we investigate the dynamic response of the system containing single and double impurities to an external exponential magnetic field at different degrees of anisotropy. We have demonstrated that the ergodicity of the system can be controlled by varying the strength and location of the impurities as well as the degree of anisotropy of the coupling.