Coherent and Incoherent Excitations of Electron-Doped SrTiO3.
Resonant photoemission at the Ti 2p and O 1s edges on a Nb-doped SrTiO(3) thin film revealed that the coherent state (CS) at the Fermi level (E(F)) had a mainly Ti 3d character whereas the incoherent in-gap state (IGS) positioned approximately 1.5 eV below E(F) had a mixed character of Ti 3d and O 2p states. This indicates that the IGS is formed by a spectral-weight transfer from the CS and subsequent spectral-weight redistribution through d-p hybridization. We discuss the evolution of the excitation spectrum with 3d band filling and rationalize the IGS through a mechanism similar to that proposed by Haldane and Anderson.
Ishida
Yukiaki
Y
RIKEN SPring-8 Center, Sayo, Sayo, Hyogo 679-5148, Japan.
Eguchi
Ritsuko
R
Matsunami
Masaharu
M
Horiba
Koji
K
Taguchi
Munetaka
M
Chainani
Ashish
A
Senba
Yasunori
Y
Ohashi
Haruhiko
H
Ohta
Hiromichi
H
Shin
Shik
S