Anomalous and spin Hall effects in hcp cobalt from GGA + U calculations

Abstract

We have calculated the intrinsic anomalous and spin Hall conductivities, spin and orbital magnetic moments and also spin polarization of Hall currentsin hexagonal cobalt within the density functional theory with the generalized gradient approximation (GGA) plus on-site Coulomb interaction (GGA+$U$). The accurate all-electron full-potential linearized augmented plane wave method is used. We find that the anomalous Hall conductivity (AHC) (${\sigma }_{xy}^A$) and orbital magnetic moment ($m_o$) of cobalt with the magnetization being along the c-axis ($m//c$) calculated in the GGA+$U$ scheme with $U=1.6$ eV and $J=0.9$ eV agree rather well with the corresponding experimental values while, in contrast, the ${\sigma }_{xy}^A$ and $m_o$ from the GGA calculations are significantly smaller than the measured ones. This suggests that moderate $U=1.6$ eV and $J=0.9$ eV are appropriate for Co metals. The calculated AHC and spin Hall conductivity (SHC) (${\sigma }^S$) are highly anisotropic, and the ratio of the Hall conductivity for $m//c$ to that for the magnetization being in-plane ($m//ab$) from the GGA+$U$ calculations, is $\sim$16.0 for the AHC and $\sim$6.0 for the SHC. For $m//c$, the spin-up and spin-down Hall currents are found to flow in the same direction. The magnitude of the calculated Hall current spin polarization ($P^H$) is large and $P^H=-0.61$. Remarkably, for $m//ab$, the spin-up and spin-down Hall currents are predicted to flow in the opposite directions. This indicates that the Hall current contains both spin-polarized charge current and pure spin current, resulting in the magnitude of the Hall current spin polarization ($P^H=-1.59$) being larger than 1.0.

References in corpus (13)

• Dissipationless Quantum Spin Current at Room Temperature
• Direct electronic measurement of the spin Hall effect
• First Principles Calculation of Anomalous Hall Conductivity in Ferromagnetic bcc Fe
• Linear magnetization dependence of the intrinsic anomalous Hall effect
• Extrinsic Spin Hall Effect Induced by Iridium Impurities in Copper
• Sign Changes of Intrinsic Spin Hall Effect in Semiconductors and Simple Metals: First-Principles Calculations
• Temperature Dependence of the Intrinsic Anomalous Hall Effect in Nickel
• Anisotropic spin Hall effect from first principles
• Enhanced spin Hall effect by resonant skew scattering in orbital-selective Kondo effect
• Ab Initio Theory of Scattering-Independent Anomalous Hall Effect
• Robust half-metallic antiferromagnets La$A$VOsO${}_6$ and La$A$Mo$Y$O${}_6$ ($A$ = Ca, Sr, Ba; $Y$ = Re, Tc) from first-principles calculations
• Intrinsic anomalous Hall effect in nickel: An GGA+U study
• On calculating the Berry curvature of Bloch electrons using the KKR method

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