Europhys. Lett.
Volume 63, Number 1, July 2003
Page(s) 97 - 103
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 01 June 2003
DOI: 10.1209/epl/i2003-00483-y
Europhys. Lett., 63 (1) , pp. 97-103 (2003)

Absence of orbital-dependent Mott transition in $\chem{Ca}$ 2-x $\chem{Sr}$ x $\chem{RuO_4}$

A. Liebsch

Institut für Festkörperforschung, Forschungszentrum Jülich - 52425 Jülich, Germany

(Received 31 January 2003; accepted in final form 6 May 2003)

The Mott transition between the metallic and insulating paramagnetic phases of the layer perovskite $\chem{Ca}$ 2-x $\chem{Sr}$ x $\chem{RuO_4}$ is analyzed within the Dynamical Mean Field Theory. To simulate the band narrowing caused by finite $\chem{Ca}$ doping concentrations, quasi-particle spectra appropriate for $\chem{Sr_{2}RuO_4}$ are evaluated for increasing values of the on-site Coulomb energy U. At small U the planar geometry splits the t2g bands near $E_{\ab{F}}$ into a wide, two-dimensional dxy band and two narrow, nearly one-dimensional dxz,yz bands. At larger U, however, the spectral distribution of these states exhibits similar correlation features, suggesting a common metal-insulator transition for all t2g bands at the same critical U.

71.20.Be - Transition metals and alloys.
71.27.+a - Strongly correlated electron systems; heavy fermions.
79.60.Bm - Clean metal, semiconductor, and insulator surfaces.

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