日 時：2010年4月9日(金曜日) 15:30-17:00
講 師：Prof. Paul C.W. Chu
(Texas Center for Superconductivity, the University of Huston)
題 目：“A Perspective of Room Temperature Superconductors
Three years after celebrating the 53rd anniversary of the BCS theory and the 23rd anniversary of the discovery of high temperature superconductivity (HTS), it appears most fitting for us to contemplate the possibility of very high temperature superconductivity (VHTS) or even room temperature superconductivity (RTS). VHTS/RTS, if achieved, can profoundly change the world. Unfortunately, VHTS/RTS has long been considered by some to belong to the domain of science fiction and to occur only at an astronomical distance and under an astronomical pressure. With the advent of liquid nitrogen superconductivity in 1987, the outlook has become much brighter. Currently, there appears to be no reason, either theoretical or experimental, why VHTS/RTS would be impossible. The recent discovery of the new class of Fe-pnictide HTSs fuels more cautious optimism. Since its inception, BCS theory has provided the basic framework for the occurrence and understanding of superconductivity, but it has failed to show where and how to find superconductivity at a higher temperature. This may be attributed to the strong coupling between the parameters in the BCS theory and the small energy scale of superconductivity in comparison with those of other excitations in the solids. After examining existing data, we believe that a holistic multidisciplinary enlightened empirical approach appears to be the most effective way to discover novel superconductors with higher transition temperatures.
紹介教員： 岩佐義宏 教授、為ヶ井 強 准教授