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Intrinsic anomalous Hall effect in nickel: An GGA+U study
- Source :
- Phys. Rev. B 84, 144427 (2011)
- Publication Year :
- 2011
-
Abstract
- The electronic structure and intrinsic anomalous Hall conductivity of nickel have been calculated based on the generalized gradient approximation (GGA) plus on-site Coulomb interaction (GGA+U) scheme. It is found that the intrinsic anomalous Hall conductivity ($\sigma_{xy}^H$) obtained from the GGA+U calculations with $U = 1.9$ eV and $J=1.2$ eV, is in nearly perfect agreement with that measured recently at low temperatures while, in contrast, the $\sigma_{xy}^H$ from the GGA calculations is about 100% larger than the measured one. This indicates that, as for the other spin-orbit interaction (SOI)-induced phenomena in 3$d$ itinerant magnets such as the orbital magnetic magnetization and magnetocrystalline anisotropy, the on-site electron-electron correlation, though moderate only, should be taken into account properly in order to get the correct anomalous Hall conductivity. The intrinsic $\sigma_{xy}^H$ and the number of valence electrons ($N_e$) have also been calculated as a function of the Fermi energy ($E_F$). A sign change is predicted at $E_F = -0.38$ eV ($N_e = 9.57$), and this explain qualitatively why the theoretical and experimental $\sigma_{xy}^H$ values for Fe and Co are positive. It is also predicted that fcc Ni$_{(1-x)}$Co(Fe,Cu)$_x$ alloys with $x$ being small, would also have the negative $\sigma_{xy}^H$ with the magnitude being in the range of $500\sim 1400$ $\Omega^{-1}$cm$^{-1}$. The most pronounced effect of including the on-site Coulomb interaction is that all the $d$-dominant bands are lowered in energy relative to the $E_F$ by about 0.3 eV, and consequently, the small minority spin X$_2$ hole pocket disappears. The presence of the small X$_2$ hole pocket in the GGA calculations is attributed to be responsible for the large discrepancy in the $\sigma_{xy}^H$ between theory and experiment.<br />Comment: 7 pages, 3 figures; Accepted for publication in Physical Review B
- Subjects :
- Condensed Matter - Strongly Correlated Electrons
Subjects
Details
- Database :
- arXiv
- Journal :
- Phys. Rev. B 84, 144427 (2011)
- Publication Type :
- Report
- Accession number :
- edsarx.1107.3242
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1103/PhysRevB.84.144427