Predicted defect induced vortex core switching in thin magnetic nanodisks

TL;DR

This paper explores how artificial defects in magnetic nanodisks can induce vortex core switching, revealing new behaviors in vortex dynamics influenced by defect size, position, and disk geometry.

Contribution

It introduces the novel phenomenon of vortex core switching caused by vortex-hole interactions in nanodisks with specific defect configurations.

Findings

Vortex core can switch when interacting with a single hole under special conditions.

Presence of a second antidot alters vortex dynamics significantly.

Vortex oscillates at high frequency around defect after trapping.

Abstract

We investigate the influence of artificial defects (small holes) inserted into magnetic nanodisks on the vortex core dynamics. One and two holes (antidots) are considered. In general, the core falls into the hole but, in particular, we would like to remark an interesting phenomenon not yet observed, which is the vortex core switching induced by the vortex-hole interactions. It occurs for the case with only one hole and for very special conditions involving the hole size and position as well as the disk size. Any small deformation in the disk geometry such as the presence of a second antidot changes completely the vortex dynamics and the vortex core eventually falls into one of the defects. After trapped, the vortex center still oscillates with a very high frequency and small amplitude around the defect center.