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Title: Electronic structure and the origin of the Dzyaloshinskii-Moriya interaction in MnSi

Here, the metallic helimagnet MnSi has been found to exhibit skyrmionic spin textures when subjected to magnetic fields at low temperatures. The Dzyaloshinskii-Moriya (DM) interaction plays a key role in stabilizing the skyrmion state. With the help of first-principles calculations, crystal field theory and a tight-binding model we study the electronic structure and the origin of the DM interaction in the B20 phase of MnSi. The strength of $$\vec{D}$$ parameter is determined by the magnitude of the spin-orbit interaction and the degree of orbital mixing, induced by the symmetry-breaking distortions in the B20 phase. We find that, strong coupling between Mn-$d$ and Si-$p$ states lead to a mixed valence ground state $$|d^{7-x}p^{2+x}\rangle$$ configuration. The experimental magnetic moment of $$0.4~\mu_B$$ is consistent with the Coulomb-corrected DFT+$U$ calculations, which redistributes electrons between the majority and minority spin channels. We derive the magnetic interaction parameters $J$ and $$\vec{D}$$ for Mn-Si-Mn superexchange paths using Moriya's theory assuming the interaction to be mediated by $$e_g$$ electrons near the Fermi level. Finally, using parameters from our calculations, we get reasonable agreement with the observations.
Authors:
 [1] ;  [2]
  1. Univ. of Missouri, Columbia, MO (United States)
  2. Univ. of Missouri, Columbia, MO (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
Grant/Contract Number:
AC05-00OR22725; FG02-00ER45818
Type:
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 93; Journal Issue: 19; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY
OSTI Identifier:
1252152
Alternate Identifier(s):
OSTI ID: 1250555

Satpathy, S., and Shanavas, K. V.. Electronic structure and the origin of the Dzyaloshinskii-Moriya interaction in MnSi. United States: N. p., Web. doi:10.1103/PhysRevB.93.195101.
Satpathy, S., & Shanavas, K. V.. Electronic structure and the origin of the Dzyaloshinskii-Moriya interaction in MnSi. United States. doi:10.1103/PhysRevB.93.195101.
Satpathy, S., and Shanavas, K. V.. 2016. "Electronic structure and the origin of the Dzyaloshinskii-Moriya interaction in MnSi". United States. doi:10.1103/PhysRevB.93.195101. https://www.osti.gov/servlets/purl/1252152.
@article{osti_1252152,
title = {Electronic structure and the origin of the Dzyaloshinskii-Moriya interaction in MnSi},
author = {Satpathy, S. and Shanavas, K. V.},
abstractNote = {Here, the metallic helimagnet MnSi has been found to exhibit skyrmionic spin textures when subjected to magnetic fields at low temperatures. The Dzyaloshinskii-Moriya (DM) interaction plays a key role in stabilizing the skyrmion state. With the help of first-principles calculations, crystal field theory and a tight-binding model we study the electronic structure and the origin of the DM interaction in the B20 phase of MnSi. The strength of $\vec{D}$ parameter is determined by the magnitude of the spin-orbit interaction and the degree of orbital mixing, induced by the symmetry-breaking distortions in the B20 phase. We find that, strong coupling between Mn-$d$ and Si-$p$ states lead to a mixed valence ground state $|d^{7-x}p^{2+x}\rangle$ configuration. The experimental magnetic moment of $0.4~\mu_B$ is consistent with the Coulomb-corrected DFT+$U$ calculations, which redistributes electrons between the majority and minority spin channels. We derive the magnetic interaction parameters $J$ and $\vec{D}$ for Mn-Si-Mn superexchange paths using Moriya's theory assuming the interaction to be mediated by $e_g$ electrons near the Fermi level. Finally, using parameters from our calculations, we get reasonable agreement with the observations.},
doi = {10.1103/PhysRevB.93.195101},
journal = {Physical Review B},
number = 19,
volume = 93,
place = {United States},
year = {2016},
month = {5}
}