Abstract
The correlation-driven metal-insulator transition (MIT) of 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 electrons is superimposed on the isotropic hopping conduction of localized electrons. The “bad-metal” character and the weak anisotropy are the consequences of the large effective mass and scattering rate of the quasiparticles in the band. There is a pseudogap above , and in the insulating phase the gap follows the BCS-like temperature dependence of the structural order parameter with in the ground state. The MIT is described in terms of a weakly coupled two-band model.
- Received 13 February 2006
DOI:https://doi.org/10.1103/PhysRevLett.96.186402
©2006 American Physical Society