Separation of orbital contributions to the optical conductivity of BaVS(3).
The correlation-driven metal-insulator transition (MIT) of BaVS(3) was studied by polarized infrared spectroscopy. In the metallic state two types of electrons coexist at the Fermi energy: the quasi-1D metallic transport of A(1g) electrons is superimposed on the isotropic hopping conduction of localized E(g) electrons. The "bad-metal" character and the weak anisotropy are the consequences of the large effective mass m(eff) approximately 7 m(e) and scattering rate Gamma > or = 160 meV of the quasiparticles in the A(1g) band. There is a pseudogap above T(MI) = 69 K, and in the insulating phase the gap follows the BCS-like temperature dependence of the structural order parameter with Delta(ch) approximately 42 meV in the ground state. The MIT is described in terms of a weakly coupled two-band model.
Kézsmárki
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I
Electron Transport Research Group of the Hungarian Academy of Science and Department of Physics, Budapest University of Technology and Economics, 1111 Budapest, Hungary.
Mihály
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G
Gaál
R
R
Barisić
N
N
Akrap
A
A
Berger
H
H
Forró
L
L
Homes
C C
CC
Mihály
L
L