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Orbital-selective Mass Enhancements in Multi-band Ca$_{2-x}$Sr$_{x}$RuO$_{4}$ Systems Analyzed by the Extended Drude Model

J. S. Lee·S. J. Moon·T. W. Noh·S. Nakatsuji·Y. Maeno
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Abstract

We investigated optical spectra of quasi-two-dimensional multi-band Ca$% _{2-x} $Sr$_{x}$RuO$_{4}$ systems. The extended Drude model analysis on the ab-plane optical conductivity spectra indicates that the effective mass should be enhanced near $x=0.5$. Based on the sum rule argument, we showed that the orbital-selective Mott-gap opening for the $d_{yz/zx}$ bands, the widely investigated picture, could not be the origin of the mass enhancement. We exploited the multi-band effects in the extended Drude model analysis, and demonstrated that the intriguing heavy mass state near $x=0.5$ should come from the renormalization of the $d_{xy}$ band.

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J. S. Lee, S. J. Moon, T. W. Noh, S. Nakatsuji, Y. Maeno. 2005-08-09. Orbital-selective Mass Enhancements in Multi-band Ca$_{2-x}$Sr$_{x}$RuO$_{4}$ Systems Analyzed by the Extended Drude Model. https://doi.org/10.1103/physrevlett.96.057401

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