Random field effects on the isotropic quantum Heisenberg model with Gaussian random magnetic field distribution

TL;DR

This study investigates how Gaussian random magnetic fields influence the phase transition behavior of the isotropic quantum Heisenberg model on 2D and 3D lattices using effective field theory, revealing second-order transitions and no reentrant behavior.

Contribution

It provides a detailed analysis of the effects of Gaussian random magnetic fields on the phase transitions of the quantum Heisenberg model using EFT-2, including phase diagrams and critical field values.

Findings

Critical temperatures are of second order.

Reentrant behavior does not occur.

Critical Gaussian field widths where T_c=0 are identified.

Abstract

Effect of Gaussian random magnetic field distribution which is centered at zero on the phase transition properties of isotropic quantum Heisenberg model has been investigated on two (2D) and three dimensional (3D) lattices within the framework of effective field theory (EFT) for a two spin cluster (which is abbreviated as EFT-2). Beside the phase diagrams and the evolution of the magnetization versus temperature curves with the Gaussian magnetic field distribution width, critical Gaussian distribution width values, which make the critical temperature zero, have been obtained for several lattices. Moreover, it has been concluded that all critical temperatures are of the second order and reentrant behavior does not exist in the phase diagrams.