Dynamical corrections to density-functional theory for quasiparticles in ferromagnetic 4f systems. I. T = 0 results for EuO

Journal Article · Fri May 01 04:00:00 EDT 1987 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.35.7015· OSTI ID:6089686

Nolting, W; Borstel, G; Borgiel, W

A theory for the electronic quasiparticle spectrum of ferromagnetic 4f systems is presented and applied to the semiconductor EuO. The starting point is a d-f exchange model, which we solve exactly for T = 0. One of the results is a simple relationship between the spin-up quasiparticle energies and the ''free'' Bloch energies epsilon-c/sub m/(k), which we use to fix the epsilon-c/sub m/(k) in a highly realistic manner by performing a new self-consistent spin-polarized band-structure calculation based on density-functional theory. With the so-determined Bloch energies we investigate the spin-down quasiparticle spectrum, which exhibits even at T = 0 strong many-body effects as a consequence of spin-exchange processes between localized magnetic 4f moments and itinerant conduction electrons. We discuss in detail the spin-down quasiparticle spectral density for the GAMMAL direction, which should be observable in an inverse photoemission experiment. The shape of this function is strongly k dependent, revealing different types of quasiparticles. The prominent quasiparticle peaks in the spin-down quasiparticle spectral density are used to construct a quasiparticle band structure, which shows some striking deviations from the one-particle solution of the density-functional theory. Furthermore, results for the electronic self-energy and the quasiparticle density of states are presented.

• Research Organization: Institut fuer Theoretische Physik II, Westfaelische Wilhelms Universitaet, D-4400 Muenster Domagkstrasse 75, Federal Republic of Germany
• OSTI ID: 6089686
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 35:13; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ABSOLUTE ZERO TEMPERATURE
BLOCH THEORY
CHALCOGENIDES
ELECTRONIC STRUCTURE
EMISSION
EUROPIUM COMPOUNDS
EUROPIUM OXIDES
MAGNETIC SEMICONDUCTORS
MATERIALS
ORIENTATION
OXIDES
OXYGEN COMPOUNDS
PHOTOEMISSION
QUASI PARTICLES
RARE EARTH COMPOUNDS
SECONDARY EMISSION
SEMICONDUCTOR MATERIALS
SPIN ORIENTATION