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arXiv · 1705.05296

Momentum-dependent susceptibilities and magnetic exchange in bcc iron from supercell DMFT calculations

A. S. Belozerov·A. A. Katanin·V. I. Anisimov
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Abstract

We analyze the momentum- and temperature dependences of the magnetic susceptibilities and magnetic exchange interaction in paramagnetic bcc iron by a combination of density functional theory and dynamical mean-field theory (DFT+DMFT). By considering a general derivation of the orbital-resolved effective model for spin degrees of freedom for Hund's metals, we relate momentum-dependent susceptibilities in the paramagnetic phase to the magnetic exchange. We then calculate non-uniform orbital-resolved susceptibilities at high-symmetry wave vectors by constructing appropriate supercells in the DMFT approach. Extracting the irreducible parts of susceptibilities with respect to Hund's exchange interaction, we determine the corresponding orbital-resolved exchange interactions, which are then interpolated to the whole Brillouin zone. Using the spherical model we estimate the temperature dependence of the resulting exchange between local moments.

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A. S. Belozerov, A. A. Katanin, V. I. Anisimov. 2017-05-15. Momentum-dependent susceptibilities and magnetic exchange in bcc iron from supercell DMFT calculations. https://doi.org/10.1103/physrevb.96.075108

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