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Center for Nonlinear Studies |
Magnetic interactions give rise to a surprising amount of complexity due to the fact that both static and dynamic magnetic properties are governed by competing short-range exchange interactions and long-range dipolar coupling. Even though the underlying dynamical equations are well established, the connection of magnetization dynamics to other degrees of freedom, such as charge and heat flow, make magnetism a mesoscale research problem that is still wide open for exploration [1]. Synthesizing magnetic materials and heterostructures with tailored properties allows to take advantage of magnetic interactions spanning many-length scales, which can be probed with magnetic microscopy and modeled with micromagnetic simulations. In this talk, I will discuss magnetic skyrmions as an example for the ensuing complexity. Magnetic skyrmions are spin configurations with a distinct topology, which result in quasi-particle-like behavior of individual skyrmions. I will show how the combination of charge currents and spin-orbit coupling (spin Hall effects) [2] can be used to electrically manipulate skyrmions at room temperature. Furthermore, using inhomogeneous electric charge currents even allows the generation of skyrmions in a process that is remarkably similar to the droplet formation in surface-tension driven fluid flows [3].
This work was supported by the U.S. Department of Energy, Office of Science, Materials Sciences and Engineering Division. Lithographic patterning was carried out at the Center for Nanoscale Materials, an Office of Science user facility, which is supported by DOE, Office of Science, Basic Energy Sciences under Contract No. #DE-AC02-06CH11357.
References
1. A. Hoffmann and H. Schultheiß, Curr. Opin. Solid State Mater. Sci. (2014); doi:10.1016/j.cossms.2014.11.004.
2. A. Hoffmann, IEEE Trans. Magn. 49, 5172 (2013).
3. W. Jiang, et al., Science (2015); doi:10.1126/science.aaa1442.
Host: Shizeng Lin