Electronic properties and transport phenomena in nearly antiferromagnetic Fermi liquids

Abstract

The behaviors of the Hall coefficient (R(sub H)) and the resistivity (rho) of nearly Antiferromagnetic (AF) metals have been studied. The causes of the difference of R(sub H) observed between the hole doped compounds and the electron doped compounds in spite of their similar hole like Fermi surface have been investigated taking account of the strong AF fluctuation. The vertex corrections for the current have been studied, and found that various anomalous behavior of R(sub H) in high T(sub c) cupric oxides could be explained. It was found that both the temperature and the doping dependence of R(sub H) in high-T(sub c) cupric oxides were well reproduced by numerical calculations based on the Fluctuation Exchange (FLEX) approximation. The expressions and the equations used for the analysis of the single band Hubbard model have been described. The calculated temperature dependence of rho and R(sub H) for high-T(sub c) cupric oxides were shown in figures. The electronic properties of the layered organic superconductors kappa-(BEDT(Bis(ethylenedithio))-TTF(Tetrafuluvalene))2X have been investigated by using the FLEX approximation and the anisotropic triangular lattice Hubbard model. It was found that d-wave like superconductivity was realized by the strong AF fluctuations. It was found that the spin-fluctuation theory was successful in reproducing the essential electronic properties for both of high-T(sub c) cupric oxides and kappa-(BEDT-TTF)2X.

近反強磁性(AF)金属のホール係数(R(sub H))および抵抗率(ρ)の挙動を研究した。両者とも同じ正孔に似たフェルミ面を有しているにもかかわらず、観測された正孔ドープ化合物と電子ドープ化合物間のR(sub H)の差異の原因を強いAFゆらぎを考慮に入れて検討した。カレントに対するバーテックス補正を研究し、高温超伝導銅酸塩におけるR(sub H)の様々な異常挙動を説明可能であることが分かった。高温超伝導銅酸塩におけるR(sub H)の温度とドーピング依存性は、ゆらぎ交換(FLEX)近似に基づく数値計算により十分に再現されることが分かった。単一バンドハバード模型の解析に用いる表式や方程式を記述した。高温超伝導銅酸塩についてのρとR(sub H)の温度依存性計算値を図示した。層状有機超伝導体κ-(BEDT-TTF)2Xの電子特性をFLEX近似と異方性3角格子ハバード模型を用いて検討した。d-波動状超伝導が強いAFゆらぎにより出現することが分かった。スピンゆらぎ理論が高温超伝導銅酸塩とκ-(BEDT(ビス(エチレンジチオ)-TTF(テトラチアフルバレン))2Xの双方に対して本質的な電子特性をうまく再現することが分かった。