Grant-in-Aid for Scientific Research (B)
|Allocation Type||Single-year Grants |
|Research Institution||Tokyo Metropolitan University |
SAKAI Osamu Tokyo Metropolitan University, Graduate School of science, Professor, 理学研究科, 教授 (60005957)
SHIMIZU Yukihiro Tohoku University, Graduate School of Engineering, Associate Professor, 大学院・工学研究科, 講師 (70250727)
SASO Tetsuro Saitama University, School of Science, Professor, 理学部, 教授 (90142926)
KANETA Yasunori University of Tokyo, Graduate School of Engineering, Research associate, 大学院・工学研究科, 助手 (00262048)
SHIINA Ryousuke Tokyo Metropolitan University, Graduate School of Science, Research associate, 理学研究科, 助手 (30326011)
IMADA Shin Tokyo Metropolitan University, Graduate School of Engineering Science, 大学院・基礎工学研究科, 助教授 (90240837)
斯波 弘行 神戸大学, 理学部, 教授 (30028196)
|Project Period (FY)
2002 – 2004
Completed (Fiscal Year 2004)
|Budget Amount *help
¥10,800,000 (Direct Cost: ¥10,800,000)
Fiscal Year 2004: ¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 2003: ¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 2002: ¥6,400,000 (Direct Cost: ¥6,400,000)
|Keywords||dynamical mean field theory / Ce compounds / band calculation / LMTO / DMFT / NCA / Ce / CeSb / 動的平均場理論 / 高分解能光電効果 / 金属強磁性合金 / 近藤絶縁体 / 多重極秩序 / 動的平均場 / 磁気光効果 / 熱起電力 / 動的クラスター近似 / バルク敏感光電子分光 / CeB_6 / CsCoCl_3|
The main purposes of this project were to development the band calculation method based on the dynamical mean field theory for general use, and to study related phenomena of strongly correlated electron systems.
(1) A method named as NCAf2v' was developed to solve the auxiliary single site Kondo problem. This enables us to include the correct exchange process through the f1-f2 valence fluctuation along with the f1-f0 fluctuation. The usual NCA method restricts the latter one.
(2) The band calculation program was developed by the combination of the LMTO and the NCAf2v' method. The spin-orbit (SO) splitting and the crystalline filed splitting (CF) of the self energy were included in the calculation.
(3) The method was applied to Ce metal and CeSb.
In the y-phase of Ce metal, the CF splitting energy is larger than the Kondo temperature, while in the a-phase the Kondo temperature is larger than the CF splitting. The SO side peak becomes conspicuous in photo-emission-spectra similarly to the experimental results.
In CeSb two peaks structure of PBS was reproduced. A rather higher Kondo temperature is expected because a small peak appears at the Fermi energy in the effective hybridization, which is caused by the strongly correlated 4f band.
The magnetic alloy problem of 3d metals was also studied. The Curie temperature id decreased by the correlation type fluctuation effects.
The optical and thermoelectric effects of Kondo insulator materials such as YbB12 were studied based on the tight biding model which reproduces the main features of band structures.
The dynamical excitation of multipolar ordering systems such as PrOs4Sb12 was also studied.