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arXiv · 1603.07544

Interplay of Coulomb interaction and spin-orbit coupling

Jörg Bünemann·Thorben Linneweber·Ute Löw·Frithjof B. Anders·Florian Gebhard
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Abstract

We employ the Gutzwiller variational approach to investigate the interplay of Coulomb interaction and spin-orbit coupling in a three-orbital Hubbard model. Already in the paramagnetic phase we find a substantial renormalization of the spin-orbit coupling that enters the effective single-particle Hamiltonian for the quasi-particles. Only close to half band-filling and for sizable Coulomb interaction we observe clear signatures of Hund's atomic rules for spin, orbital, and total angular momentum. For a finite local Hund's-rule exchange interaction we find a ferromagnetically ordered state. The spin-orbit coupling considerably reduces the size of the ordered moment, it generates a small ordered orbital moment, and it induces a magnetic anisotropy. To investigate the magnetic anisotropy energy, we use an external magnetic field that tilts the magnetic moment away from the easy axis $(1,1,1)$.

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Jörg Bünemann, Thorben Linneweber, Ute Löw, Frithjof B. Anders, Florian Gebhard. 2016-03-24. Interplay of Coulomb interaction and spin-orbit coupling. https://doi.org/10.1103/physrevb.94.035116

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