uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Theory of noncollinear interactions beyond Heisenberg exchange: Applications to bcc Fe
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
Univ Iceland, Sci Inst, IS-107 Reykjavik, Iceland.;ITMO Univ, Dept Nanophoton & Metamat, St Petersburg 197101, Russia..
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
Show others and affiliations
2017 (English)In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 96, no 14, article id 144413Article in journal (Refereed) Published
Abstract [en]

We show for a simple noncollinear configuration of the atomistic spins (in particular, where one spin is rotated by a finite angle in a ferromagnetic background) that the pairwise energy variation computed in terms of multiple-scattering formalism cannot be fully mapped onto a bilinear Heisenberg spin model even in the absence of spin-orbit coupling. The non-Heisenberg terms induced by the spin-polarized host appear in leading orders in the expansion of the infinitesimal angle variations. However, an E-g - T-2g symmetry analysis based on the orbital decomposition of the exchange parameters in bcc Fe leads to the conclusion that the nearest-neighbor exchange parameters related to the T-2g orbitals are essentially Heisenberg-like: they do not depend on the spin configuration, and can, in this case, be mapped onto a Heisenberg spin model even in extreme noncollinear cases.

Place, publisher, year, edition, pages
AMER PHYSICAL SOC , 2017. Vol. 96, no 14, article id 144413
National Category
Physical Sciences
Identifiers
URN: urn:nbn:se:uu:diva-340146DOI: 10.1103/PhysRevB.96.144413ISI: 000412699400003OAI: oai:DiVA.org:uu-340146DiVA, id: diva2:1177922
Funder
Swedish Research CouncilKnut and Alice Wallenberg Foundation, 2012.0031Knut and Alice Wallenberg Foundation, 2013.0020EU, FP7, Seventh Framework Programme, 600382Available from: 2018-01-26 Created: 2018-01-26 Last updated: 2018-04-07Bibliographically approved
In thesis
1. Electronic structure and exchange interactions from ab initio theory: New perspectives and implementations
Open this publication in new window or tab >>Electronic structure and exchange interactions from ab initio theory: New perspectives and implementations
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

In this thesis, the magnetic properties of several materials were investigated using first principle calculations. The ab initio method named real space linear muffin-tin orbitals atomic sphere approximation (RS-LMTO-ASA) was used to calculate the electronic structure and magnetic properties of bulk systems, surface and nanostructures adsorbed on surfaces.

We have implemented new features in the RS-LMTO-ASA method, such as the calculation of (a) Bloch Spectral Function (BSF), (b) orbital resolved Jij and (c) Dzyaloshinskii-Moriya interaction (DMI). Using (a), we have shown that one can calculate the dispersion relation for bulk systems using a real space method. Furthermore, the dispersion relation was revealed to be existent even for finite one-dimensional structures, such as the Mn chain on Au(111) and Ag(111) surfaces. With (b), we have investigated the orbital resolved exchange coupling parameter Jij for 3d metals. It is demonstrated that the nearest neighbor (NN) interaction for bcc Fe has intriguing behavior, however, the contribution coming from the T2g orbitals favours the anti-ferromagnetic coupling behavior. Moreover, the Fermi surface for bcc Fe is formed mostly by the T2g orbitals and these are shown to be highly Heisenberg-like, i.e. do not depend significantly on the magnetic configuration. Later, the same approach was used to study other transition metals, such as Cr, Mn, Co and Ni. In the end, we have presented the results obtained with the implementation (c). Our results have shown the large dependence of the DMI values, both the strength and direction, with respect to which magnetic configuration they are calculated from. We argue that, for the investigated systems, the non-collinearity induces currents (spin and charge) that will influence directly the DMI vectors.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2018. p. 85
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1663
Keywords
ab initio, exchange interactions, non-collinear magnetism
National Category
Condensed Matter Physics
Research subject
Physics with spec. in Atomic, Molecular and Condensed Matter Physics
Identifiers
urn:nbn:se:uu:diva-347812 (URN)978-91-513-0315-4 (ISBN)
Public defence
2018-05-29, Seminar Room, Universidade Federal do Pará, Av. Augusto Correa 01, Belém, PA, Brazil, Belém, 10:00 (English)
Opponent
Supervisors
Note

The public defence can also be followed on livestream at Rosetta room, Ång/10239, Ångströmlaboratoriet, Lägerhyddsvägen 1, Uppsala

Available from: 2018-05-07 Created: 2018-04-07 Last updated: 2018-05-07

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full text

Authority records BETA

Szilva, AttilaThonig, DannyKvashnin, YaroslavRodrigues, Debora C. M.Pereiro, ManuelNordström, LarsEriksson, Olle

Search in DiVA

By author/editor
Szilva, AttilaThonig, DannyKvashnin, YaroslavRodrigues, Debora C. M.Pereiro, ManuelNordström, LarsEriksson, Olle
By organisation
Materials Theory
In the same journal
Physical Review B
Physical Sciences

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 5 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf