Transfer of spectral weight and symmetry across the metal-insulator transition in VO(2).
We present a detailed study of the valence and conduction bands of VO2 across the metal-insulator transition using bulk-sensitive photoelectron and O K x-ray absorption spectroscopies. We observe a giant transfer of spectral weight with distinct features that require an explanation which goes beyond the Peierls transition model as well as the standard single-band Hubbard model. Analysis of the symmetry and energies of the bands reveals the decisive role of the V 3d orbital degrees of freedom. Comparison to recent realistic many body calculations shows that much of the k dependence of the self-energy correction can be cast within a dimer model.
Koethe
T C
TC
II. Physikalisches Institut, Universität zu Köln, Zülpicher Strasse 77, D-50937 Köln, Germany.
Hu
Z
Z
Haverkort
M W
MW
Schüssler-Langeheine
C
C
Venturini
F
F
Brookes
N B
NB
Tjernberg
O
O
Reichelt
W
W
Hsieh
H H
HH
Lin
H-J
HJ
Chen
C T
CT
Tjeng
L H
LH