Direct Observation of a Localized Magnetic Soliton in a Spin-Transfer Nanocontact

D. Backes, F. Macià, S. Bonetti, R. Kukreja, H. Ohldag, and A. D. Kent

Phys. Rev. Lett. 115, 127205 – Published 17 September 2015

Abstract

We report the direct observation of a localized magnetic soliton in a spin-transfer nanocontact using scanning transmission x-ray microscopy. Experiments are conducted on a lithographically defined 150 nm diameter nanocontact to an ultrathin ferromagnetic multilayer with perpendicular magnetic anisotropy. Element-resolved x-ray magnetic circular dichroism images show an abrupt onset of a magnetic soliton excitation localized beneath the nanocontact at a threshold current. However, the amplitude of the excitation $≃ 25 °$ at the contact center is far less than that predicted ( $⪅ 180 °$ ), showing that the spin dynamics is not described by existing models.

Received 3 April 2015

DOI:https://doi.org/10.1103/PhysRevLett.115.127205

Authors & Affiliations

D. Backes^1,*, F. Macià^1,2, S. Bonetti^3,4, R. Kukreja^3,5, H. Ohldag^1,6, and A. D. Kent¹

¹Department of Physics, New York University, 4 Washington Place, New York, New York 10003, USA
²Grup de Magnetisme, Departament de Física Fonamental, Universitat de Barcelona, Barcelona 08028, Spain
³Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sandhill Road, Menlo Park, California 94025, USA
⁴Department of Physics, Stanford University, Stanford, California 94305, USA
⁵Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
⁶Stanford Synchrotron Radiation Laboratory, 2575 Sandhill Road, Menlo Park, California 94025, USA