Basic Theory of Superconducting Transistor and Superconducting Superlattice

1. 超导晶体管的基本理论现代微工艺技术的发展，制造出了与半导体耦合的超导晶体管。从电子态的角度阐明了库柏对的微观行为，揭示了S-N和S-N- s结体系的一些新性质。例如，通过Gorkov方程的精确解，得到了对势的真实微观特征，并在此基础上阐明了S和N的材料性质、邻近效应强度之间的关系。通过解析得到了Gorkov方程的积分核，并精确地确定了其解。得到了超导转变温度Tc作为超晶格周期d的函数，对于较大的d区，Tc由于邻近效应而随d逐渐减小，但对于较小的d区，Tc使振荡成为d的函数。这可以用电子波的布拉格反射效应来解释。我们研究了材料的宏观各向异性如何反映库珀对的内部结构，反过来又如何影响超导的各向异性。特别是，在包含层间和层内电子-电子势的模型中，Tc和Cooper对的结构如何取决于材料参数。对4进行了进一步的研究。利用弹道准粒子和5.隧道光谱。层状材料的超导性。

1. Basic theory of the superconducting transistorThanks 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 modelThe 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 anisotropyWe 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.