|Budget Amount *help
¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1994 : ¥400,000 (Direct Cost : ¥400,000)
Fiscal Year 1993 : ¥600,000 (Direct Cost : ¥600,000)
|Keywords||History of Physics, / History of Magnetism, / History of Quantum Mechanics, / Electron Spin, / Ampere's Molecular Current, / Barnett effect, / Einstein-de Haas effect, / Magneto-Mechanical effect. / 磁気角運動量比 / ランデの因子 / 原子磁気モーメント / スピン磁気モーメント / 量子力学 / 磁性物理学|
1. Firstly, as an introductive study on the title, the hystorical development of the classical quantum theory and magnetism is reviewed. And it has been pointed out that there are two hystorical ways to approach the magnetism to the quantum theory, as follows.
(1) The discovering process on the relation of atomic magnetic moment and electron spin, and,
(2) the other process, on the interactive mechanical force between atomic magnetic moments in solid and the quantum mechanical exchange interaction between atomic spins.
2. According to the above (1) , the role of the magneto-mechanical experiment in the history of establishment of concept on the electron spin was investigated. The first postulation of the elementary magnetic moment was Ampere's molecular current in 1823. But, this postulation was not noticed by people, because nothing was known about the electric current and electrons in solid, in the age of Ampere's. After about 70 years latter, it has become a common sense that the elect
ron, one of the constituents of common material, has its own charge and mass, and its motion is the cause of electric current in solid. The magneto-mechanical effect, which is based on the concept that the magnetic moment must has mechanical moment individualy, has become to postulate. And the magneto-mecanical ratio was estimated theoretically, then the experimental trials were done by Barnett (1914) , and by Einstain-de Haas (1915) , respectively. But, their results equally showed that the estimated ratio of angular momentum and magnetic moment (magneto-mechanical ratio) was about one half of the theoretical estimation, then it was called the magneto-mecanical anomaly. Soon after of these trials, it has been thought taht the elementary magnetic moment may depend upon the electron spin rather than orbital angular motion, on the analogy of the case of anomalous Zeeman effect. The compleat solution of these pro blems are obtaned by P.A.M.Dirac, who has constructed the relastivitic quantum mechanical theory (1928).
Details of these study are published on "BUTURIGAKUSI" , No.8 (1995) , in Japanese, pub. BUTURIGAKUSI-KENKYUUKAI,c/o H.Konno, Dept.Phys.Yokohama Nat'1.Univ. Less