講座內(nèi)容：The Research Institute for Interdisciplinary Science (RIIS) was established in April 2016 to advance the study of physics and fundamental biological science. In particular, RIISpursues neutrino physics using laser spectroscopy, the fabrication of artificial photosynthesis systems as well as the clarification of the structure and mechanism of photosynthesis, the design of superconducting materials with a high superconducting critical temperature and new functional materials for future electronic devices, and the elucidation of the properties of energy storage materials using a theoretical approach. Furthermore, RIIS aims at producing new functional materials and devices through interdisciplinary collaboration among the above fields. In this talk, I will introduce the outline of organization and research activity of RIIS.

In our group, many superconductors have been prepared by an electron doping of two-dimensional(2D) layered materials (FeSe1-zTez, MoSe2, phenacene and graphite). The first technique for electron doping is an intercalation of alkali and alkali earth metal atoms to the materials, and several metal-doped 2D layered materials showed the superconductivity. The highest Tc realized in our group is 49 K at21 GPa in (NH3)yCsxFeSe. The second technique is an electrostatic electron doping. We fabricated the LaOBiS2 electric-double-layer (EDL) transistor and applied gate voltage to LaOBiS2 single crystal through the EDL capacitor. The superconductivity was observed at 4 K, and it was tuned by the applied gate voltage. Thus, the superconductivity was electrostatically induced. In this talk, I will give a talk on our recent superconductivity research.