Geometric symmetry and size-dependent skyrmion phase transitions in magnetic nanostructures

TL;DR

This study explores how geometric symmetry and size influence skyrmion phase transitions in magnetic nanostructures, revealing symmetry-dependent behaviors and stability conditions relevant for spintronic device design.

Contribution

It demonstrates the critical role of geometric symmetry in controlling skyrmion states and phase transitions in various nanostructures, providing insights for spintronic applications.

Findings

Nanodisks enable rich topological phase transitions with increasing diameter.

Square and rectangular nanostructures suppress topological complexity due to corner effects.

Perpendicular magnetic fields induce transitions between skyrmion and skyrmionium states in nanodisks.

Abstract

We investigate the interplay of geometric symmetry, size, and external magnetic fields in regulating individual skyrmion states within magnetic nanostructures. By analyzing nanodisks, nanosquares, and nanorectangles, we demonstrate that rotational symmetry in nanodisks enables rich topological phase transitions, from ferromagnetic states to skyrmions, skyrmioniums, and multi-states, as their diameter increases. In contrast, square and rectangular structures exhibit suppressed topological complexity due to corner-induced demagnetization effects and reduced symmetries. Under perpendicular magnetic fields, nanodisks show field-driven transitions between skyrmionium and skyrmion states. By leveraging asymmetry, square and rectangular nanostructures stabilize skyrmions over a broader parameter range than nanodisks. These findings highlight geometric symmetry as a critical design parameter for tailoring skyrmion stability and functionality in spintronic applications such as multi-state memory and reconfigurable logic devices.