Strong, anisotropic in-plane and out-of-plane damping-like spin-orbit torque in epitaxial RuO<sub>2</sub>

ORAL

Abstract

We study spin torques in RuO2/Permalloy bilayers grown on TiO2 substrates by second-harmonic Hall and spin-torque ferromagnetic resonance techniques [1]. Epitaxial RuO2 films exhibit a strong out-of-plane damping-like torque (OOP-DLT) that is anisotropic as a function of the orientation of current flow relative to the RuO2 crystal axes. This OOP-DLT is absent in similarly prepared IrO2/Permalloy samples despite the fact that RuO2 and IrO2 possess similar crystal structures [2]. This suggests that the recently-discovered antiferromagnetism in RuO2 [3] provides the symmetry breaking that allows the OOP-DLT [4]. We also observe a sizable in-plane damping-like torque originating from RuO2.

[1] arXiv:1801.09636
[2] arXiv:2006.04365
[3] PRL 118, 077201 (2017)
[4] arXiv:2002.07073

*This work made use of the Cornell Center for Materials Research Shared Facilities which are supported through the NSF MRSEC program (DMR-1719875) and in part at the Cornell NanoScale Facility, a member of the National Nanotechnology Coordinated Infrastructure (NNCI), which is supported by the National Science Foundation (Grant NNCI-2025233).

Presenters

  • Arnab Bose

    • Cornell University

Authors

  • Arnab Bose

    • Cornell University
  • Nathaniel Schreiber

    • Department of Materials Science and Engineering, Cornell University
    • Cornell University
  • Hari Nair

    • Cornell University
    • Department of Materials Science and Engineering, Cornell University
  • Xiyue S Zhang

    • School of Applied and Engineering Physics, Cornell University
    • Cornell University
  • Rakshit Jain

    • Cornell University
  • Thow Min Jerald Cham

    • Cornell University
  • Jiaxin Sun

    • Department of Materials Science and Engineering, Cornell University
    • Cornell University
  • David Anthony Muller

    • Cornell University
    • School of Applied and Engineering Physics, Cornell University
  • Robert Alan Buhrman

    • Cornell University
  • Darrell Schlom

    • Cornell University
    • Cornell university
    • Department of Materials Science and Engineering, Cornell University
  • Daniel C Ralph

    • Cornell University