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Electronic Structure of YbB6: Is it a Topological Insulator or Not?
- Source :
-
Physical Review Letters . Mar2016, Vol. 116 Issue 11, p1-1. 1p. - Publication Year :
- 2016
-
Abstract
- To finally resolve the controversial issue of whether or not the electronic structure of YbB6 is nontrivially topological, we have made a combined study using angle-resolved photoemission spectroscopy (ARPES) of the nonpolar (110) surface and density functional theory (DFT). The flat-band conditions of the (110) ARPES avoid the strong band bending effects of the polar (001) surface and definitively show that YbB6 has a topologically trivial B 2p-Yb 5d semiconductor band gap of ~0.3 eV. Accurate determination of the low energy band topology in DFT requires the use of a modified Becke-Johnson exchange potential incorporating spin-orbit coupling and an on-site Yb 4f Coulomb interaction U as large as 7 eV. The DFT result, confirmed by a more precise GW band calculation, is similar to that of a small gap non-Kondo nontopological semiconductor. Additionally, the pressure-dependent electronic structure of YbB6 is investigated theoretically and found to transform into a p-d overlap semimetal with small Yb mixed valency. [ABSTRACT FROM AUTHOR]
- Subjects :
- *ELECTRONIC structure
*TOPOLOGICAL insulators
*PHOTOELECTRON spectroscopy
Subjects
Details
- Language :
- English
- ISSN :
- 00319007
- Volume :
- 116
- Issue :
- 11
- Database :
- Academic Search Index
- Journal :
- Physical Review Letters
- Publication Type :
- Academic Journal
- Accession number :
- 116938729
- Full Text :
- https://doi.org/10.1103/PhysRevLett.116.116401