Spin-neutral Currents for Spintronics

Authors

Ding-Fu Shao, University of Nebraska-LincolnFollow
Shu-Hui Zhang, Beijing University of Chemical Technology
Ming Li, University of Nebraska-LincolnFollow
Chang-Beom Eom, University of Wisconsin-MadisonFollow
Evgeny Y. Tsymbal, University of Nebraska-LincolnFollow

ORCID IDs

Shao http://orcid.org/0000-0002-2732-4131

Zhang http://orcid.org/0000-0001-5820-3853

Tsymbal http://orcid.org/0000-0002-6728-5480

Document Type

Article

Date of this Version

2021

Citation

Nature Communications (2021) 12: 7061

doi: 10.1038/s41467-021-26915-3

Comments

Copyright 2021, the authors. Open access

License: CC BY 4.0 International

Abstract

Electric currents carrying a net spin polarization are widely used in spintronics, whereas globally spin-neutral currents are expected to play no role in spin-dependent phenomena. Here we show that, in contrast to this common expectation, spin-independent conductance in compensated antiferromagnets and normal metals can be efficiently exploited in spintronics, provided their magnetic space group symmetry supports a non-spin-degenerate Fermi surface. Due to their momentum-dependent spin polarization, such antiferromagnets can be used as active elements in antiferromagnetic tunnel junctions (AFMTJs) and produce a giant tunneling magnetoresistance (TMR) effect. Using RuO₂ as a representative compensated antiferromagnet exhibiting spin-independent conductance along the [001] direction but a non-spin-degenerate Fermi surface, we design a RuO₂/TiO₂/RuO₂ (001) AFMTJ, where a globally spin-neutral charge current is controlled by the relative orientation of the Néel vectors of the two RuO₂ electrodes, resulting in the TMR effect as large as ~500%. These results are expanded to normal metals which can be used as a counter electrode in AFMTJs with a single antiferromagnetic layer or other elements in spintronic devices. Our work uncovers an unexplored potential of the materials with no global spin polarization for utilizing them in spintronics.