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

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 et al. [JETP 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 ≈ 0.35 dilution concentrations, that well coincides with the Sykes and Essam theory. Further dilution leads to the phase transition disappearance.

Elevated effective dimension in tree-like nanomagnetic Cayley structures

“…The extensive degeneracy and nature of the ground state in spin glasses have been an area of extensive research over multiple decades, resulting in theoretical spin glass models that became, among other examples, the basis of error-correcting codes 7 , problems of optimization 8 , and brain science paradigms 9,10 . Inspired by recent research on artificial frustrated systems [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] , a first step towards the realization of artificial Ising spin glasses was made recently 29 . There, Ising-type single-domain nanomagnets are lithographically arranged onto Gaussian random sites and orientations with a controlled degree of disorder, the feature commonly believed to be the main ingredient in spin glasses.…”

Mean-field phase diagram and spin-glass phase of the dipolar kagome Ising antiferromagnet

“…2), and another completely different (fourfold degenerate) ordered phase emerges. This observation highlights the importance of accounting for the dipolar interaction as accurately as possible, in order to recover the correct de-scription of the ordered phase [74].…”

Multispin Monte Carlo Method

“…Мы рассчитали НМ-методом одну из конфигураций вырожденного основного состояния системы диполей искусственного спинового льда на решетке кагоме, рисунок 2. Радиус диполь-дипольного взаимодействия ограничивался нами до трех координационных сфер, в соответствии с выводами, приведенными в работе [18]. Каждый диполь ядра имел 14 ближайших соседей, ядро состояло из 6 диполей.…”