Skyrmion Dynamics in a Double-Disk Geometry under an Electric Current

Nanomaterials (Basel). 2022 Sep 6;12(18):3086. doi: 10.3390/nano12183086.

Abstract

In this work, we present an analysis of skyrmion dynamics considering Dzyaloshinskii-Moriya interactions in an STNO device with a double-disk geometry. Three regimes were observed as a function of geometric parameters and the electric current density: (i) the skyrmion is annihilating at the system's border; (ii) the skyrmion moves in a non-circular trajectory alternating its position between the two disks, and (iii) the skyrmion only rotates inside a one-disk subsystem. For the annihilation state, we found that the transient time decays within a stretched exponential law as a function of the electric current. Our results show a 2D state diagram that can guide new experimental work in order to obtain these specific behaviors for new applications based on skyrmion dynamics.

Keywords: dynamics; magnetic skyrmions; micromagnetism; spin torque nano-oscillators.

Grants and funding

We acknowledge partial financial support from the Centers of excellence with BASAL/ANID financing, Grant AFB180001, CEDENNA. We also acknowledge financial support from ANID/FONDECYT, grant numbers 1200867 and 1220215, respectively. V.L.C.-S. thanks the Brazilian agency CNPq (Grant n. 302084/2019-3) for financial support.