Berlin 2015 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 15: Focus Session: Skyrmionics: Future of Spintronics? (jointly with MA)

TT 15.2: Topical Talk

Montag, 16. März 2015, 15:30–16:00, H 0104

Topological Transport Phenomena in Magnetic Skyrmion Matter — •Markus Garst — Institut für Theoretische Physik, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany

Magnetic skyrmions are topological textures with a finite winding number – similar to the baryon number in nuclear matter – which is at the origin of various novel transport phenomena. It is directly reflected in a strong spin-Magnus force in their effective equation of motion resulting in a peculiar dynamics with skyrmions preferentially moving along equipotential lines akin to guiding centers of electrons in Landau levels. This not only allows for an efficient manipulation by spin currents but also enables skyrmions to avoid pinning centers giving rise to spintronic phenomena at ultralow threshold currents [1]. Moreover, the adiabatic motion of electrons in skyrmion textures results in an emergent electrodynamics revealed by a topological Hall effect and a skyrmion-flow Hall effect [2]. Interesting spin-thermal transport and skyrmion caloritronic phenomena are also to be expected in insulators. The topological winding number is manifest in the magnon-skyrmion scattering potential and, for example, leads to magnon skew scattering and a magnon Hall effect. In turn, the magnon pressure generated, e.g., by a thermal gradient induces, counterintuitively, a skyrmion motion towards the hot region, i.e., the magnon source [3].

[1] F. Jonietz et al., Science 330, 1648 (2010)

[2] T. Schulz et al., Nat. Phys. 8, 301 (2012)

[3] C. Schütte and M. Garst, Phys. Rev. B 90, 094423 (2014)