A Monte Carlo study of random surface field effect on layering transitions

TL;DR

This study uses Monte Carlo simulations to explore how random surface magnetic fields influence layering transitions in a spin-1/2 Ising thin film, revealing dependence on disorder concentration and external conditions.

Contribution

It provides new insights into the impact of bimodal surface field disorder on layering transitions and critical disorder concentrations in Ising thin films.

Findings

Layering transition critical concentration decreases with increasing surface magnetic field.

Layer magnetizations and spin distributions vary significantly with disorder and external fields.

Disorder influences the sign change and discontinuous behavior of layer magnetizations.

Abstract

The effect of a random surface field, within the bimodal distribution, on the layering transitions in a spin-1/2 Ising thin film is investigated, using Monte Carlo simulations. It is found that the layering transitions depend strongly on the concentration $p$ of the disorder of the surface magnetic field, for a fixed temperature, surface and external magnetic fields. Indeed, the critical concentration $p_c(k)$ at which the magnetisation of each layer $k$ changes the sign discontinuously, decreases for increasing the applied surface magnetic field, for fixed values of the temperature $T$ and the external magnetic field $H$. Moreover, the behaviour of the layer magnetisations as well as the distribution of positive and negative spins in each layer, are also established for specific values of $H_s$, $H$, $p$ and the temperature $T$. \\