Anomalous spin–orbit torques in magnetic single-layer films

Wenrui Wang, Tao Wang, Vivek P. Amin, Yang Wang, Anil Radhakrishnan, Angie Davidson, Shane R. Allen, T. J. Silva, Hendrik Ohldag, Davor Balzar, Barry L. Zink, Paul M. Haney, John Q. Xiao, David G. Cahill, Virginia O. Lorenz, Xin Fan

Research output: Contribution to journalLetter

Abstract

The spin Hall effect couples charge and spin transport1–3, enabling electrical control of magnetization4,5. A quintessential example of spin-Hall-related transport is the anomalous Hall effect (AHE)6, first observed in 1880, in which an electric current perpendicular to the magnetization in a magnetic film generates charge accumulation on the surfaces. Here, we report the observation of a counterpart of the AHE that we term the anomalous spin–orbit torque (ASOT), wherein an electric current parallel to the magnetization generates opposite spin–orbit torques on the surfaces of the magnetic film. We interpret the ASOT as being due to a spin-Hall-like current generated with an efficiency of 0.053 ± 0.003 in Ni80Fe20, comparable to the spin Hall angle of Pt7. Similar effects are also observed in other common ferromagnetic metals, including Co, Ni and Fe. First-principles calculations corroborate the order of magnitude of the measured values. This work suggests that a strong spin current with spin polarization transverse to the magnetization can be generated within a ferromagnet, despite spin dephasing8. The large magnitude of the ASOT should be taken into consideration when investigating spin–orbit torques in ferromagnetic/non-magnetic bilayers.

Original languageEnglish (US)
Pages (from-to)819-824
Number of pages6
JournalNature Nanotechnology
Volume14
Issue number9
DOIs
StatePublished - Sep 1 2019

Fingerprint

torque
Torque
Magnetic films
Magnetization
Hall effect
Electric currents
Spin Hall effect
magnetic films
electric current
Spin polarization
Ferromagnetic materials
magnetization
Hall currents
polarization
metals

ASJC Scopus subject areas

  • Bioengineering
  • Atomic and Molecular Physics, and Optics
  • Biomedical Engineering
  • Materials Science(all)
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

Cite this

Wang, W., Wang, T., Amin, V. P., Wang, Y., Radhakrishnan, A., Davidson, A., ... Fan, X. (2019). Anomalous spin–orbit torques in magnetic single-layer films. Nature Nanotechnology, 14(9), 819-824. https://doi.org/10.1038/s41565-019-0504-0

Anomalous spin–orbit torques in magnetic single-layer films. / Wang, Wenrui; Wang, Tao; Amin, Vivek P.; Wang, Yang; Radhakrishnan, Anil; Davidson, Angie; Allen, Shane R.; Silva, T. J.; Ohldag, Hendrik; Balzar, Davor; Zink, Barry L.; Haney, Paul M.; Xiao, John Q.; Cahill, David G.; Lorenz, Virginia O.; Fan, Xin.

In: Nature Nanotechnology, Vol. 14, No. 9, 01.09.2019, p. 819-824.

Research output: Contribution to journalLetter

Wang, W, Wang, T, Amin, VP, Wang, Y, Radhakrishnan, A, Davidson, A, Allen, SR, Silva, TJ, Ohldag, H, Balzar, D, Zink, BL, Haney, PM, Xiao, JQ, Cahill, DG, Lorenz, VO & Fan, X 2019, 'Anomalous spin–orbit torques in magnetic single-layer films', Nature Nanotechnology, vol. 14, no. 9, pp. 819-824. https://doi.org/10.1038/s41565-019-0504-0
Wang W, Wang T, Amin VP, Wang Y, Radhakrishnan A, Davidson A et al. Anomalous spin–orbit torques in magnetic single-layer films. Nature Nanotechnology. 2019 Sep 1;14(9):819-824. https://doi.org/10.1038/s41565-019-0504-0
Wang, Wenrui ; Wang, Tao ; Amin, Vivek P. ; Wang, Yang ; Radhakrishnan, Anil ; Davidson, Angie ; Allen, Shane R. ; Silva, T. J. ; Ohldag, Hendrik ; Balzar, Davor ; Zink, Barry L. ; Haney, Paul M. ; Xiao, John Q. ; Cahill, David G. ; Lorenz, Virginia O. ; Fan, Xin. / Anomalous spin–orbit torques in magnetic single-layer films. In: Nature Nanotechnology. 2019 ; Vol. 14, No. 9. pp. 819-824.
@article{bd8dcb046f6c44e0b39ab74f50a32fb4,
title = "Anomalous spin–orbit torques in magnetic single-layer films",
abstract = "The spin Hall effect couples charge and spin transport1–3, enabling electrical control of magnetization4,5. A quintessential example of spin-Hall-related transport is the anomalous Hall effect (AHE)6, first observed in 1880, in which an electric current perpendicular to the magnetization in a magnetic film generates charge accumulation on the surfaces. Here, we report the observation of a counterpart of the AHE that we term the anomalous spin–orbit torque (ASOT), wherein an electric current parallel to the magnetization generates opposite spin–orbit torques on the surfaces of the magnetic film. We interpret the ASOT as being due to a spin-Hall-like current generated with an efficiency of 0.053 ± 0.003 in Ni80Fe20, comparable to the spin Hall angle of Pt7. Similar effects are also observed in other common ferromagnetic metals, including Co, Ni and Fe. First-principles calculations corroborate the order of magnitude of the measured values. This work suggests that a strong spin current with spin polarization transverse to the magnetization can be generated within a ferromagnet, despite spin dephasing8. The large magnitude of the ASOT should be taken into consideration when investigating spin–orbit torques in ferromagnetic/non-magnetic bilayers.",
author = "Wenrui Wang and Tao Wang and Amin, {Vivek P.} and Yang Wang and Anil Radhakrishnan and Angie Davidson and Allen, {Shane R.} and Silva, {T. J.} and Hendrik Ohldag and Davor Balzar and Zink, {Barry L.} and Haney, {Paul M.} and Xiao, {John Q.} and Cahill, {David G.} and Lorenz, {Virginia O.} and Xin Fan",
year = "2019",
month = "9",
day = "1",
doi = "10.1038/s41565-019-0504-0",
language = "English (US)",
volume = "14",
pages = "819--824",
journal = "Nature Nanotechnology",
issn = "1748-3387",
publisher = "Nature Publishing Group",
number = "9",

}

TY - JOUR

T1 - Anomalous spin–orbit torques in magnetic single-layer films

AU - Wang, Wenrui

AU - Wang, Tao

AU - Amin, Vivek P.

AU - Wang, Yang

AU - Radhakrishnan, Anil

AU - Davidson, Angie

AU - Allen, Shane R.

AU - Silva, T. J.

AU - Ohldag, Hendrik

AU - Balzar, Davor

AU - Zink, Barry L.

AU - Haney, Paul M.

AU - Xiao, John Q.

AU - Cahill, David G.

AU - Lorenz, Virginia O.

AU - Fan, Xin

PY - 2019/9/1

Y1 - 2019/9/1

N2 - The spin Hall effect couples charge and spin transport1–3, enabling electrical control of magnetization4,5. A quintessential example of spin-Hall-related transport is the anomalous Hall effect (AHE)6, first observed in 1880, in which an electric current perpendicular to the magnetization in a magnetic film generates charge accumulation on the surfaces. Here, we report the observation of a counterpart of the AHE that we term the anomalous spin–orbit torque (ASOT), wherein an electric current parallel to the magnetization generates opposite spin–orbit torques on the surfaces of the magnetic film. We interpret the ASOT as being due to a spin-Hall-like current generated with an efficiency of 0.053 ± 0.003 in Ni80Fe20, comparable to the spin Hall angle of Pt7. Similar effects are also observed in other common ferromagnetic metals, including Co, Ni and Fe. First-principles calculations corroborate the order of magnitude of the measured values. This work suggests that a strong spin current with spin polarization transverse to the magnetization can be generated within a ferromagnet, despite spin dephasing8. The large magnitude of the ASOT should be taken into consideration when investigating spin–orbit torques in ferromagnetic/non-magnetic bilayers.

AB - The spin Hall effect couples charge and spin transport1–3, enabling electrical control of magnetization4,5. A quintessential example of spin-Hall-related transport is the anomalous Hall effect (AHE)6, first observed in 1880, in which an electric current perpendicular to the magnetization in a magnetic film generates charge accumulation on the surfaces. Here, we report the observation of a counterpart of the AHE that we term the anomalous spin–orbit torque (ASOT), wherein an electric current parallel to the magnetization generates opposite spin–orbit torques on the surfaces of the magnetic film. We interpret the ASOT as being due to a spin-Hall-like current generated with an efficiency of 0.053 ± 0.003 in Ni80Fe20, comparable to the spin Hall angle of Pt7. Similar effects are also observed in other common ferromagnetic metals, including Co, Ni and Fe. First-principles calculations corroborate the order of magnitude of the measured values. This work suggests that a strong spin current with spin polarization transverse to the magnetization can be generated within a ferromagnet, despite spin dephasing8. The large magnitude of the ASOT should be taken into consideration when investigating spin–orbit torques in ferromagnetic/non-magnetic bilayers.

UR - http://www.scopus.com/inward/record.url?scp=85070234365&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85070234365&partnerID=8YFLogxK

U2 - 10.1038/s41565-019-0504-0

DO - 10.1038/s41565-019-0504-0

M3 - Letter

C2 - 31332346

AN - SCOPUS:85070234365

VL - 14

SP - 819

EP - 824

JO - Nature Nanotechnology

JF - Nature Nanotechnology

SN - 1748-3387

IS - 9

ER -