Dresden 2009 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 3: Correlated Electrons: Spin Systems and Itinerant Magnets 1
TT 3.7: Vortrag
Montag, 23. März 2009, 12:00–12:15, HSZ 304
Spin Torque Effects in a Helical Magnet — •Florian Jonietz1, Sebastian Mühlbauer1,2, Christian Pfleiderer1, Rembert Duine3, Benedikt Binz4, Achim Rosch4, Andreas Neubauer1, Robert Ritz1, Stefan Legl1, Wolfgang Münzer1, Robert Georgii2, and Peter Böni1 — 1Physik Department E21, Technische Universität München — 2Forschungsneutronenquelle Heinz Maier-Leibnitz FRM II — 3Institute for Theoretical Physics, Utrecht University — 4ITP, University of Cologne
Spin torque interactions in soft ferromagnets are a promising route to novel spintronics devices. In these systems the spin torque is due to changes of the orientation of the spin-polarization of the conduction electrons in non-colinear spin structures, notably Bloch domain walls. A major constraint of these studies is the extrinsic nature of magnetic pinning in soft ferromagnets requiring very large current densities of order 1012 A/m2. We report AC susceptibility and neutron scattering measurements in the A-Phase of MnSi, a two-dimensional skyrmion lattice [1], as a function of electric DC currents. The non-colinear spin structure is here intrinsic and due to Dzyaloshinsky-Moriya interactions, resulting in a very small pinning. We find distinct features that suggest spin torque effects at current densities that are 5 to 6 orders of magnitude smaller than those observed in soft ferromagnets. This identifies helical magnets as a new route to exploiting spin torque effects in novel spintronic applications.
[1] S. Mühlbauer, B. Binz, F. Jonietz, C. Pfleiderer, A. Rosch, R. Georgii, P. Böni, in review (2008)