Influence of cutoff dipole interaction radius and dilution on phase transition in kagome artificial spin ice

TL;DR

This study examines how the cutoff dipole interaction radius and dilution affect the phase transition and thermodynamic properties of kagome artificial spin ice, emphasizing the importance of considering at least three coordination spheres for accurate modeling.

Contribution

It determines the minimum number of coordination spheres needed to preserve collective phenomena and analyzes the effects of dilution on phase transition behavior in kagome artificial spin ice.

Findings

At least three coordination spheres with 14 neighbors are necessary.

Increasing the interaction radius lowers the phase transition temperature.

Phase transition persists up to approximately 35% dilution, aligning with Sykes and Essam theory.

Abstract

The investigations carried out in this paper show the influence of cutoff dipole interaction radius and dilution on the basic thermodynamic characteristics of the kagome artificial spin ice with free boundary conditions. The phase transition disappearance at the dipole interaction radius limitation was shown in our previous study by Shevchenko {\it et al.} [JETP {\bf 124}(6), 982-993 (2017)]. This work continues this study and answers the question of the coordination spheres numbers that must be taken into account, in order not to lose the basic collective phenomena. The answer is at least three coordination spheres with 14 nearest neighbors must be taken into account for kagome artificial spin ice. Restriction to a smaller cutoff radius leads to significant changes in the thermodynamic behavior of the main characteristics of the system. An increase of the interaction radius shifts the phase transition temperature to the low-temperature area. The effects of dilution on kagome artificial spin ice were also investigated. It is shown that the phase transition occurs up to $p_c\approx0.35$ dilution concentrations, that well coincides with the Sykes and Essam theory. Further dilution leads to the phase transition disappearance.