Excitonic insulator state in Ta2NiSe5 probed by photoemission spectroscopy.
Phys Rev Lett
; 103(2): 026402, 2009 Jul 10.
Article
in En
| MEDLINE
| ID: mdl-19659224
ABSTRACT
We report on a photoemission study of Ta2NiSe5 that has a quasi-one-dimensional structure and an insulating ground state. Ni 2p core-level spectra show that the Ni 3d subshell is partially occupied and the Ni 3d states are heavily hybridized with the Se 4p states. In angle-resolved photoemission spectra, the valence-band top is found to be extremely flat, indicating that the ground state can be viewed as an excitonic insulator state between the Ni 3d-Se 4p hole and the Ta 5d electron. We argue that the high atomic polarizability of Se plays an important role to stabilize the excitonic state.
Search on Google
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Phys Rev Lett
Year:
2009
Document type:
Article
Affiliation country:
Japón