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Title: Topological Hall effect in diffusive ferromagnetic thin films with spin-flip scattering

In this paper, we study the topological Hall (TH) effect in a diffusive ferromagnetic metal thin film by solving a Boltzmann transport equation in the presence of spin-flip scattering. A generalized spin-diffusion equation is derived which contains an additional source term associated with the gradient of the emergent magnetic field that arises from skyrmions. Because of the source term, spin accumulation may build up in the vicinity of the skyrmions. This gives rise to a spin-polarized diffusion current that in general suppresses the bulk TH current. Only when the spin-diffusion length is much smaller than the skyrmion size does the TH resistivity approach the value derived by Bruno et al. [Phys. Rev. Lett. 93, 096806 (2004)]. Finally, we derive a general expression of the TH resistivity that applies to thin-film geometries with spin-flip scattering, and show that the corrections to the TH resistivity become large when the size of room temperature skyrmions is further reduced to tens of nanometers.
Authors:
 [1] ;  [2]
  1. Argonne National Lab. (ANL), Argonne, IL (United States). Materials Science Division
  2. Argonne National Lab. (ANL), Argonne, IL (United States). Materials Science Division; Northwestern-Argonne Inst. of Science and Technology, Evanston, IL (United States)
Publication Date:
Grant/Contract Number:
AC02-06CH11357
Type:
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 97; Journal Issue: 13; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; skyrmions; spin accumulation; spin relaxation
OSTI Identifier:
1433913
Alternate Identifier(s):
OSTI ID: 1430774

Zhang, Steven S. -L., and Heinonen, Olle. Topological Hall effect in diffusive ferromagnetic thin films with spin-flip scattering. United States: N. p., Web. doi:10.1103/PhysRevB.97.134401.
Zhang, Steven S. -L., & Heinonen, Olle. Topological Hall effect in diffusive ferromagnetic thin films with spin-flip scattering. United States. doi:10.1103/PhysRevB.97.134401.
Zhang, Steven S. -L., and Heinonen, Olle. 2018. "Topological Hall effect in diffusive ferromagnetic thin films with spin-flip scattering". United States. doi:10.1103/PhysRevB.97.134401.
@article{osti_1433913,
title = {Topological Hall effect in diffusive ferromagnetic thin films with spin-flip scattering},
author = {Zhang, Steven S. -L. and Heinonen, Olle},
abstractNote = {In this paper, we study the topological Hall (TH) effect in a diffusive ferromagnetic metal thin film by solving a Boltzmann transport equation in the presence of spin-flip scattering. A generalized spin-diffusion equation is derived which contains an additional source term associated with the gradient of the emergent magnetic field that arises from skyrmions. Because of the source term, spin accumulation may build up in the vicinity of the skyrmions. This gives rise to a spin-polarized diffusion current that in general suppresses the bulk TH current. Only when the spin-diffusion length is much smaller than the skyrmion size does the TH resistivity approach the value derived by Bruno et al. [Phys. Rev. Lett. 93, 096806 (2004)]. Finally, we derive a general expression of the TH resistivity that applies to thin-film geometries with spin-flip scattering, and show that the corrections to the TH resistivity become large when the size of room temperature skyrmions is further reduced to tens of nanometers.},
doi = {10.1103/PhysRevB.97.134401},
journal = {Physical Review B},
number = 13,
volume = 97,
place = {United States},
year = {2018},
month = {4}
}

Works referenced in this record:

Colloquium: Topological insulators
journal, November 2010