Berlin 2012 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 25: Focussed session: Frontiers of electronic structure theory: Strong correlations from first principles II (jointly with TT)

O 25.5: Vortrag

Dienstag, 27. März 2012, 11:45–12:00, HE 101

T-matrix approach for electron-magnon interactions in ferromagnetic materials — •Mathias C.T.D. Müller, Christoph Friedrich, Ersoy Sasioglu, and Stefan Blügel — Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany

Recent ARPES experiments [1,2] indicate that the scattering between electrons and magnons taking place in systems with localized d and f orbitals leads to a pronounced renormalization of the electron band dispersion, creating a kink near the Fermi energy very similar to the renormalization due to electron-phonon coupling. In order to describe this renormalization from first principles we use the T-matrix formalism, which describes the correlated motion of an electron-hole pair of opposite spins in terms of ladder diagrams. The multiple scattering gives rise to collective spin excitations [3]. Through emitting and absorption of these magnons, the energy of an electron propagating through a spin-polarized system gets renormalized. Our implementation of the corresponding self-energy correction Σ=−i G T is based on the all-electron full-potential linearized augmented-plane-wave (FLAPW) method FLEUR [4] combined with Wannier functions [5]. We present first results for elementary ferromagnets.
J. Schäfer et al., Phys. Rev. Lett. 92, 097205 (2004).
A. Hofmann et al., Phys. Rev. Lett. 102, 187204 (2009).
E. Şaşioğlu et al., Phys. Rev. B 81, 054434 (2010).
www.flapw.de
F. Freimuth et al., Phys. Rev. B 78, 035120 (2008).