Magnetic bibubble dynamics driven by magnetic field gradients

A magnetic bibubble is a composite structure involving two magnetic bubbles with topological skyrmion number N-sk = +/- 2, which can be formed by merging two individual magnetic bubbles. Unlike the normal magnetic bubble, the axial symmetry of the bibubble is thus broken, which provide us an ideal platform to study the dynamics of topological structures with skyrmion number larger than unity. In this work, we studied the dynamics of the bibubble driven by a magnetic field gradient using micromagnetic simulations. We show that both the velocity and the skyrmion hall angle depend on the angle between the field gradient and the orientation of the bibubble. Moreover, the bibubble performs an orbital motion in the presence of circular field gradients accompanying with an oscillation of its orientation.

Automated summary

The dynamics of a magnetic bibubble driven by a magnetic field gradient were studied, showing that the velocity and skyrmion hall angle depend on the angle between the field gradient and the orientation of the bibubble. Additionally, the bibubble exhibits orbital motion and orientation oscillation in the presence of circular field gradients.