Ising model with periodic pinning of mobile defects

TL;DR

This paper investigates how local pinning of mobile defects affects phase transitions in a 2D Ising model, revealing that pinning induces long-range order and influences the transition temperature, with the transition likely being first order.

Contribution

It introduces a detailed analysis of defect pinning effects on phase behavior in a 2D Ising model using Monte Carlo and transfer matrix methods, highlighting the emergence of long-range order.

Findings

Pinning induces long-range magnetic order at low temperatures.

The phase transition temperature depends on pinning strength.

The transition appears to be of first order, with or without pinning.

Abstract

A two-dimensional Ising model with short-range interactions and mobile defects describing the formation and thermal destruction of defect stripes is studied. In particular, the effect of a local pinning of the defects at the sites of straight equidistant lines is analysed using Monte Carlo simulations and the transfer matrix method. The pinning leads to a long-range ordered magnetic phase at low temperatures. The dependence of the phase transition temperature, at which the defect stripes are destabilized, on the pinning strength is determined. The transition seems to be of first order, with and without pinning.