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MA: Fachverband Magnetismus
MA 33: Correlation Theory I
MA 33.6: Vortrag
Mittwoch, 18. März 2020, 11:00–11:15, HSZ 403
Methods of electron transport in the theory of spin stiffness — •Ilja Turek1, Josef Kudrnovsky2, and Vaclav Drchal2 — 1Institute of Physics of Materials, Czech Acad. Sci., Brno, Czech Rep. — 2Institute of Physics, Czech Acad. Sci., Prague, Czech Rep.
We present an ab initio theory of the spin-wave stiffness for itinerant ferromagnets with pair exchange interactions derived from the magnetic force theorem [1]. The resulting formula involves one-particle Green's functions and effective velocity operators appearing in a recent theory of electron transport [2]. Application of this approach to clean crystals allows one to overcome the problem of nonconvergent lattice summations, as documented by results for pure metals Fe, Co, and Ni. Application to random alloys within the coherent potential approximation, illustrated by results for fcc Ni-Fe and bcc Fe-Al systems, enables one to include the disorder-induced vertex corrections, often neglected in evaluation of the exchange interactions.
[1] A. I. Liechtenstein et al., J. Magn. Magn. Mater. 67 (1987) 65. [2] I. Turek et al., Phys. Rev. B 65 (2002) 125101.