Coherent and Incoherent Excitations of Electron-DopedSrTiO3

Yukiaki Ishida, Ritsuko Eguchi, Masaharu Matsunami, Koji Horiba, Munetaka Taguchi, Ashish Chainani, Yasunori Senba, Haruhiko Ohashi, Hiromichi Ohta, Shik Shin
2008 Physical Review Letters  
Resonant photoemission at the Ti 2p and O 1s edges on a Nb-doped SrTiO3 thin film revealed that the coherent state (CS) at the Fermi level (EF) had mainly Ti 3d character whereas the incoherent in-gap state (IGS) positioned ~1.5 eV below EF had 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
more » ... on spectrum with 3d band filling and rationalize the IGS through a mechanism similar to that proposed by Haldane and Anderson.
doi:10.1103/physrevlett.100.056401 pmid:18352398 fatcat:7dh4owopprbazj3f7gjbuxowui