SCIENCE SPIN-OFFS

[dockzef]

Stability and Lifetime of Antiferromagnetic Skyrmions

P. F. Bessarab, D. Yudin, D. R. Gulevich, P. Wadley, M. Titov, Oleg A. Tretiakov
(Submitted on 13 Sep 2017)

The two-dimensional Heisenberg exchange model with out-of-plane anisotropy and Dzyaloshinskii-Moriya interaction (DMI) is employed to investigate the lifetime and stability of antiferromagnetic (AFM) skyrmion as a function of temperature and external magnetic field. An isolated AFM skyrmion is shown to be metastable at zero temperature in a certain parameter range set by the anisotropy and DMI strength. In the limit of vanishing DMI, the skyrmion size is shrinking and the uniform AFM state becomes the only minimum of the energy functional. In the opposite limit of large DMI, the skyrmion size is diverging and the system eventually undergoes a phase transition to a stripe domain state. We show that the magnetic field has no profound effect on the system properties unless the corresponding energy scale becomes comparable with the antiferromagnetic exchange energy. In such strong fields, the stability of the AFM skyrmion is further enhanced, which is in contrast to the effect of the field on its ferromagnetic counterpart.

https://arxiv.org/abs/1709.04454