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Suppressed Coherence due to Orbital Correlations in the Ferromagnetically Ordered Metallic Phase of Mn Compounds

Masatoshi Imada
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Abstract

Small Drude weight $D$ together with small specific heat coefficient $γ$ observed in the ferromagnetic phase of R$_{1-x}$A$_x$MnO$_3$ (R=La, Pr, Nd, Sm; A=Ca, Sr, Ba) are analyzed in terms of a proximity effect of the Mott insulator. The scaling theory for the metal-insulator transition with the critical enhancement of orbital correlations toward the staggered ordering of two $e_g$ orbitals such as $3x^2-r^2$ and $3y^2-r^2$ symmetries may lead to the critical exponents of $D \propto δ^{u}$ and $γ\propto δ^v$ with $u=3/2$ and $v=0$. The result agrees with the experimental indications.

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Masatoshi Imada. 1997-11-17. Suppressed Coherence due to Orbital Correlations in the Ferromagnetically Ordered Metallic Phase of Mn Compounds. https://doi.org/10.1143/jpsj.67.45

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