Exchange interactions in itinerant magnets: the effects of local particle-hole irreducible vertex corrections and SU(2) symmetry of Hund interaction

Abstract

We study exchange interactions in iron and nickel within the DFT+DMFT approach with density-density and SU(2) symmetric Coulomb interaction. In particular, we analyze the representation of exchange interactions through the electron non-local Green's functions, connecting the local particle-hole (ph) irreducible interaction vertices. While the neglect of the local ph-irreducible vertex corrections, suggested previously within the dual fermion approach [E. A. Stepanov, et.al., Phys. Rev. Lett. {\bf 121}, 037204 (2018)], yields the result corresponding to the generalization of the magnetic force theorem approach, we argue that these vertex corrections are in fact less important for strong localized magnets, such as iron, but become more essential for weak itinerant magnets, such as nickel. At the same time, the overall account of the local vertex and self-energy corrections in the so-called renormalized magnetic force theorem approach is essential for iron, and less important for nickel. The difference of the results of density-density and SU(2) symmetric Coulomb interaction is found to be relatively small, in contrast to the Curie temperature and the value of the local magnetic moment.

12 pages, 7 figures

References in corpus (20)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Advanced capabilities for materials modelling with Quantum ESPRESSO
• Spin freezing transition and non-Fermi-liquid self-energy in a 3-orbital model
• Local magnetic moments in iron and nickel at ambient and Earth's core conditions
• Ab initio dynamical vertex approximation
• $i$QIST: An open source continuous-time quantum Monte Carlo impurity solver toolkit
• Exchange interactions and magnetic force theorem
• Superperturbation solver for quantum impurity models
• Magnetism of iron and nickel from rotationally invariant Hirsch-Fye quantum Monte Carlo calculations
• Spin dynamics of itinerant electrons: local magnetic moment formation and Berry phase
• $i$QIST v0.7: An open source continuous-time quantum Monte Carlo impurity solver toolkit
• Magnetic exchange in $\alpha$-iron from the ab initio calculations in the paramagnetic phase
• Rotationally-Invariant Exchange Interaction: The Case of Paramagnetic Iron
• Exchange interactions in iron and nickel: DFT+DMFT study in paramagnetic phase
• Extracting Kondo temperature of strongly-correlated systems from the inverse local magnetic susceptibility
• DFT+DMFT study of exchange interactions in cobalt and their implications for the competition of hcp and fcc phases
• Magnetic properties of half metal from the paramagnetic phase: DFT+DMFT study of exchange interactions in CrO${}_2$
• Dual Bethe-Salpeter equation for the multi-orbital lattice susceptibility within dynamical mean-field theory
• Reply to: "Extracting Kondo temperature of strongly-correlated systems from the inverse local magnetic susceptibility"
• Electron correlation effects in paramagnetic cobalt

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