Abstract
We investigate the band structure of BaBiO3, an insulating parent compound of doped high-Tc superconductors, using in situ angle-resolved photoemission spectroscopy on thin films. The data compare favorably overall with density functional theory calculations within the local density approximation, demonstrating that electron correlations are weak. The bands exhibit Brillouin zone folding consistent with known BiO6 breathing distortions. Though the distortions are often thought to coincide with Bi3+/Bi5+ charge ordering, core level spectra show that bismuth is monovalent. We further demonstrate that the bands closest to the Fermi level are primarily oxygen derived, while the bismuth 6s states mostly contribute to dispersive bands at deeper binding energy. The results support a model of Bi-O charge transfer in which hole pairs are localized on combinations of the O 2p orbitals.
Original language | English |
---|---|
Article number | 037002 |
Journal | Physical Review Letters |
Volume | 117 |
Issue number | 3 |
DOIs | |
State | Published - Jul 12 2016 |
Externally published | Yes |
Funding
The authors thank G.A. Sawatzky, K. Foyevtsova, and C. Mudry for insightful discussions. F. Dubi, M. Kropf, and L. Nue provided technical assistance at SIS beam line. D.J.G. received financial support from Sciex-NMSch (Project No.13.236) funded by the Swiss Confederation. Y.W. and S.J. were supported by the University of Tennessees Science Alliance Joint Directed Research and Development (JDRD) program, a collaboration with Oak Ridge National Laboratory. S.J. acknowledges additional support from the University of Tennessees Office of Research Engagements Organized Research Unit program. CPU time was provided in part by resources supported by the University of Tennessee and Oak Ridge National Laboratory Joint Institute for Computational Sciences.
Funders | Funder number |
---|---|
JDRD | |
Sciex-NMSch | 13.236 |
Swiss Confederation | |
University of Tennessees Office of Research | |
University of Tennessees Science Alliance Joint Directed Research and Development | |
Oak Ridge National Laboratory | |
University of Tennessee |