We present a combined theoretical and experimental study, investigating the origin of the enhanced nonadiabaticity of magnetic vortex cores. Scanning transmission x-ray microscopy is used to image the vortex core gyration dynamically to measure the nonadiabaticity with high precision, including a high confidence upper bound. We show theoretically, that the large nonadiabaticity parameter observed experimentally can be explained by the presence of local spin currents arising from a texture induced emergent Hall effect. This study demonstrates that the magnetic damping α and nonadiabaticity parameter β are very sensitive to the topology of the magnetic textures, resulting in an enhanced ratio (β/α>1) in magnetic vortex cores or Skyrmions.
Bibliographical noteFunding Information:
The authors acknowledge support by the German Science Foundation Grants No.DFG SFB 767, SFB TRR 173 Spin+X, KL1811, MAINZ GSC 266, the ERC No.MASPIC 2007-Stg 208162, the EU RTN Spinswitch, No.MRTN CT-2006-035327, No.MAGWIRE FP7-ICT-2009-5 257707, COMATT and the Swiss National Science Foundation. We also thank Michael Bechtel and the BESSY II staff for supporting the time-resolved studies at the HZB Berlin. The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, and of the U.S. Department of Energy under Contract No.DE-AC02-05CH11231. A.M. and C.A. are supported by the King Abdullah University of Science and Technology (KAUST) through Grant No.CRG2-R2-13-MANC-KAUST-1 from the Office of Sponsored Research (OSR).
© 2016 American Physical Society.
ASJC Scopus subject areas
- Physics and Astronomy(all)