This title appears in the Scientific Report : 2019 

Electron-magnon scattering in elementary ferromagnets from first principles: Lifetime broadening and band anomalies
Müller, Mathias C. T. D.
Blügel, Stefan / Friedrich, Christoph (Corresponding author)
Quanten-Theorie der Materialien; IAS-1
JARA - HPC; JARA-HPC
JARA-FIT; JARA-FIT
Quanten-Theorie der Materialien; PGI-1
Physical review / B covering condensed matter and materials physics, 100 (2019) 4, S. 045130
Woodbury, NY Inst. 2019
10.1103/PhysRevB.100.045130
Journal Article
Optoelectronic properties of materials for photovoltaic and photonic applications
Controlling Configuration-Based Phenomena
Controlling Spin-Based Phenomena
OpenAccess
OpenAccess
Please use the identifier: http://dx.doi.org/10.1103/PhysRevB.100.045130 in citations.
Please use the identifier: http://hdl.handle.net/2128/22526 in citations.
We study the electron-magnon scattering in bulk Fe, Co, and Ni within the framework of many-body perturbation theory implemented in the full-potential linearized augmented-plane-wave method. To this end, a k-dependent self-energy (GT self-energy) describing the scattering of electrons and magnons is constructed from the solution of a Bethe-Salpeter equation for the two-particle (electron-hole) Green function, in which single-particle Stoner and collective spin-wave excitations (magnons) are treated on the same footing. Partial self-consistency is achieved by the alignment of the chemical potentials. The resulting renormalized electronic band structures exhibit strong spin-dependent lifetime effects close to the Fermi energy, which are strongest in Fe. The renormalization can give rise to a loss of quasiparticle character close to the Fermi energy, which we attribute to electron scattering with spatially extended spin waves. This scattering is also responsible for dispersion anomalies in conduction bands of iron and for the formation of satellite bands in nickel. Furthermore, we find a band anomaly at a binding energy of 1.5 eV in iron, which results from a coupling of the quasihole with single-particle excitations that form a peak in the Stoner continuum. This band anomaly was recently observed in photoemission experiments. On the theory side, we show that the contribution of the Goldstone mode to the GT self-energy is expected to (nearly) vanish in the long-wavelength limit. We also present an in-depth discussion about the possible violation of causality when an incomplete subset of self-energy diagrams is chosen