Quenching of majority-channel quasiparticle excitations in cobalt.
The low-energy electronic excitations in cobalt are studied by a theoretical method that includes many-body effects and a realistic description of the band structure. Angle-resolved photoemission spectra measured on a thick film of hexagonal close-packed Co on Cu(111) agree well with calculated spectral functions. Because of many-body effects no sharp quasiparticle peaks exist for binding energies larger than 2 eV and in this energy region the spectrum is essentially incoherent. The many-body corrections are much stronger in the majority-spin channel and drastically affect the spin polarization of the spectra.
Monastra
S
S
INFM-S3 and Dipartimento di Fisica, Università di Modena, Via Campi 213/a, I-41100 Modena, Italy.
Manghi
F
F
Rozzi
C A
CA
Arcangeli
C
C
Wetli
E
E
Neff
H-J
HJ
Greber
T
T
Osterwalder
J
J