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MA: Magnetismus

MA 5: Spin-Structures and Magnetic Phase Transitions I

MA 5.11: Vortrag

Montag, 27. März 2006, 12:45–13:00, HSZ 403

Skyrmionic textures in chiral magnets — •U.K. Rößler¹, A.N. Bogdanov¹, and C. Pfleiderer² — ¹IFW Dresden, P.O. Box 270116, D-01171 Dresden, Germany — ²Physik Department E21, TU München, Germany

In certain non-linear field models particle-like localized states, so-called Skyrmions, can be stabilized. In condensed matter systems, Skyrmions and extended Skyrmionic textures exist, e.g., under non-equilibrium conditions in turbulent fluids, induced by external fields in Quantum Hall magnets, or stabilized by topological defects in the blue phases of liquid crystals. The talk presents new theoretical results on Skyrmionic magnetization structures in magnets with broken inversion symmetry. In these chiral systems, a particular exchange, so-called Dzyaloshinskii-Moriya interactions, stabilize vortex-like Skyrmions as string-like excitations and condensates of Skyrmions with the appearance of multiply modulated states. In phenomenological models for weakly ferromagnetic metals, Skyrmion lattices spontaneously arise as equilibrium phases. The theory explains the “partial magnetic order”, recently found in the chiral ferromagnet MnSi, as a Skyrmionic texture. Magnetic Skyrmion lattices are predicted to exist quite generally in magnetic metal films owing to the broken inversion symmetry at surfaces.