: A two-fluid incoherent metal?M. S. Laad1, L. Craco2 and E. Müller-Hartmann2
1 Department of Physics, Loughborough University - Loughborough, LE11 3TU, UK
2 Institut für Theoretische Physik, Universität zu Köln 77 Zülpicher Strasse, D-50937 Köln, Germany
received 3 September 2004; accepted in final form 14 January 2005
published online 16 February 2005
We present ab initio LDA+DMFT results for the many-particle density of states of on the metallic side of the strongly first-order (T-driven) insulator-metal transition. In strong contrast to LDA predictions, there is no remnant of even correlated Fermi-liquid behavior in the correlated metal. Excellent quantitative agreement with published photoemission and X-ray absorption experiments is found in the metallic phase. We argue that the absence of FL-quasiparticles provides a natural explanation for the bad-metallic transport for T>340. Based on this agreement, we propose that the I-M transition in is an orbital-selective Mott transition, and point out the relevance of orbital-resolved one-electron and optical spectroscopy to resolve this outstanding issue.
71.28.+d - Narrow-band systems; intermediate-valence solids.
71.30.+h - Metal-insulator transitions and other electronic transitions.
72.10.-d - Theory of electronic transport; scattering mechanisms.
© EDP Sciences 2005