Project/Area Number  08640483 
Research Category 
GrantinAid for Scientific Research (C)

Section  一般 
Research Field 
物性一般(含基礎論)

Research Institution  Nagoya University 
Principal Investigator 
KURODA Yoshihiro Nagoya Univ., Phys.Dept., Professor, 大学院・理学研究科, 教授 (60013504)

CoInvestigator(Kenkyūbuntansha) 
YOSHIOKA Hideo Nagoya Univ., Phys.Dept., Assistant, 大学院・理学研究科, 助手 (40252225)
ONO Yoshiaki Nagoya Univ., Phys.Dept., Associate Professor, 大学院・理学研究科, 助教授 (40221832)
SUZUMURA Yoshikazu Nagoya Univ., Phys.Dept., Associate Professor, 大学院・理学研究科, 助教授 (90108449)
MATSUURA Tamifusa Nagoya Univ., Phys.Dept., Professor, 大学院・理学研究科, 教授 (10022609)

Project Fiscal Year 
1996 – 1998

Project Status 
Completed(Fiscal Year 1998)

Budget Amount *help 
¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 1998 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1997 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1996 : ¥700,000 (Direct Cost : ¥700,000)

Keywords  transport phenomena / Mori formula / Kubo formula / 輸送現象 / 森公式 / 久保公式 
Research Abstract 
Very recently we have found that the ordinary perturbation technique based on the Feynrnan's diagram can be applied to calculate the Mori formura for electrical resistivity. (J.Phys. Soc. Japan 64 No.11 (1995) 40924096) The aim of the present project was to utilize the new expression of the Mori formura for examining the traditional understanding of the Mori formula itself and searching possibility of its extensive application, e.g., for calculation of the transport coefficients in many electron systems. As it should be, the Mori formula must be equivalent to the Kubo formula. In fact, we have confirmed the equivalence explicitly for resitivity due to impurity scattering and optical conductivity in 2 band systems. (J.Phys. Soc. Japan 65 No.2 (1996) 525528) Moreover, with the help of some identities which hold among dynamical correlation functions, it. has been shown that the both formulae are equivalent to each other rigorously. (J.Phys. Soc. Japan 65 No.2 (1996) 342344) However, in real systems we must rely upon the some approximation procedure and it may happen that there occurs some discrepancy between results obtained through the two formulae. In fact, it has been widely believed that when we calculate electrical resistivity the memory function approximation based on the Mori formula is more convinient to he used. Then, in order to check whether it. is really so or not, we have calculated electrical resistivity clue to the impurity scattering and also that clue to the dp hybridization term by applying the same approximation procedure to the two formulae and shown that the both results are identical and the memory function approximation is justified at high frequency limit, which invalidiate the traditional way of its application. (J.Phys. Soc. Japan 66 No.9 (1997) 27902797)。 In conclusion, we argue that the Mori formula and the Kubo formula are identical to each other as far as the same approximation procedure are applied.
