Ishida Y, Eguchi R, Matsunami M, Horiba K, Taguchi M, Chainani A, Senba Y, Ohashi H, Ohta H, Shin S. Coherent and Incoherent Excitations of Electron-Doped SrTiO3.
PHYSICAL REVIEW LETTERS 2008;
100:056401. [PMID:
18352398 DOI:
10.1103/physrevlett.100.056401]
[Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2007] [Indexed: 05/26/2023]
Abstract
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.
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