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

Direct link
Cite
Citation style
  • apa
  • harvard1
  • 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
New relativistic Hamiltonian: the Angular MagnetoElectric coupling
Univ Paris Saclay, Lab SPMS, CNRS, UMR8580,CentraleSupelec, Chatenay Malabry, France.;Univ Arkansas, Dept Phys, Fayetteville, AR 72701 USA..
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 Paris Saclay, Lab SPMS, CNRS, UMR8580,CentraleSupelec, Chatenay Malabry, France..
Show others and affiliations
2016 (English)In: Spintronics IX, 2016, UNSP 99312EConference paper, (Refereed)
Abstract [en]

Spin-Orbit Coupling (SOC) is a ubiquitous phenomenon in the spintronics area, as it plays a major role in allowing or enhancing many well-known phenomena, such as the Dzyaloshinskii-Moriya interaction, magnetocrystalline anisotropy, the Rashba effect, etc. However, the usual expression of the SOC interaction h/4 m(2)c(2) [E x p] . sigma (1) where p is the momentum operator, E the electric field, sigma the vector of Pauli matrices, breaks the gauge invariance required by the electronic Hamiltonian. On the other hand, very recently, a new phenomenological interaction, coupling the angular momentum of light and magnetic moments, has been proposed based on symmetry arguments: -xi/2[r x (E x B)] . M, (2) with M the magnetization, r the position, and xi the interaction strength constant. This interaction has been demonstrated to contribute and/or give rise, in a straightforward way, to various magnetoelectric phenomena, such as the anomalous Hall effect (AHE), the anisotropic magnetoresistance (AMR), the planar Hall effect and Rashba-like effects, or the spin -current model in multiferroics. This last model is known to be the origin of the cycloidal spin arrangement in bismuth ferrite for instance. However, the coupling of the angular momentum of light with magnetic moments lacked a fundamental theoretical basis. Starting from the Dirac equation, we derive a relativistic interaction Hamiltonian which linearly couples the angular momentum density of the electromagnetic (EM) field and the electrons spin ?. We name this coupling the Angular MagnetoElectric (AME) coupling. We show that in the limit of uniform magnetic field, the AME coupling yields an interaction exactly of the form of Eq. (2), thereby giving a firm theoretical basis to earlier works. The AME coupling can be expressed as: xi[E x A] . sigma-, (3) with A being the vector potential. Interestingly, the AME coupling was shown to be complementary to the traditional SOC, and together they restore the gauge invariance of the Hamiltonian. As an illustration of the AME coupling, we straightforwardly derived a relativistic correction to the so-called Inverse Faraday Effect (IFE), which is the emergence of an effective magnetic field under illumination by a circularly polarized light.

Place, publisher, year, edition, pages
2016. UNSP 99312E
Series
Proceedings of SPIE, ISSN 0277-786X ; 9931
Keyword [en]
Spin-Orbit, Angular MagnetoElectric coupling, Inverse Faraday Effect
National Category
Atom and Molecular Physics and Optics
Identifiers
URN: urn:nbn:se:uu:diva-316240DOI: 10.1117/12.2238196ISI: 000391482500023ISBN: 9781510602540 (print)OAI: oai:DiVA.org:uu-316240DiVA: diva2:1077293
Conference
9th Spintronics Symposium / SPIE Conference, AUG 28-SEP 01, 2016, San Diego, CA
Available from: 2017-02-27 Created: 2017-02-27 Last updated: 2017-02-27Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Mondal, RitwikBerritta, MarcoOppeneer, Peter M.
By organisation
Materials Theory
Atom and Molecular Physics and Optics

Search outside of DiVA

GoogleGoogle Scholar

Altmetric score

Total: 136 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • 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