Project/Area Number |
63540271
|
Research Category |
Grant-in-Aid for General Scientific Research (C)
|
Allocation Type | Single-year Grants |
Research Field |
物性一般(含極低温・固体物性に対する理論)
|
Research Institution | The University of Tokyo |
Principal Investigator |
TSUKADA Masaru University of Tokyo, Faculty of Science, Associate Professor, 理学部, 助教授 (90011650)
|
Co-Investigator(Kenkyū-buntansha) |
SHIMA Nobuyuki Himeji Institute of Technology, Faculty of Science, Associate Professor, 理学部, 助教授 (90167445)
|
Project Period (FY) |
1988 – 1990
|
Project Status |
Completed (Fiscal Year 1990)
|
Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1990: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1989: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1988: ¥600,000 (Direct Cost: ¥600,000)
|
Keywords | Superconducting transistor / Superconducting superlattice / Scanning tunneling spectroscopy / Josephson current / Tunnel junction / Proximity effect / 3次元S-N系 / クロ-ニッヒペニ-系 / トンネル分光 / ペアポテンシャル / ト-マシュ振動 / バリスティック電子 / ジョゼフソン電流 / 超伝導近接効果 / 超伝導-半導体接合 / 超格子超伝導系 |
Research Abstract |
1. Basic theory of the superconducting transistor Thanks to development of modern micro process technique, superconducting transistor coupled with semiconductor is fabricated. By clarifying the microscopic behavior of Cooper pairs from the view point of the electronic states, we revealed some novel properties of the S-N and S-N-S junction system. For example, by the exact solution of the Gorkov equation, real microscopic feature of the pair potential is obtained and based on it the relation between the material properties of the S and N, proximity effect strength is clarified. 2. Superconductivity in the Kronig-Penny Superlattice model The integral kernel of Gorkov equation is analytically obtained and its solution is exactly determined. The superconducting transition temperature Tc was obtained as the function of the superlattice period d. For the larger d region Tc gradually decreases with d because of the proximity effect, but for the smaller d region, Tc makes oscillation as the function of d. This is explained by the Bragg reflection effect of the electron wave. 3. Internal structure of Cooper pairs and macroscopic anisotropy We have investigated how the macroscopic anisotropy of materials reflect on the internal structure of the Cooper pairs, and in conversely how this influences anisotropy of the superconductivity. In particular, with the model including the inter- and intra- layer electron-electron potential, how Tc and structure of Cooper pair depends on material parameters. Further studies have been made on 4. Tunnel spectroscopy by means of Ballistic quasi-particles and 5. Superconductivity of layered materials.
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