I have been interested in pressure-induced phenomena such as metallization, amorphization, molecular dissociation, and superconducting transition. Until now I have studied the high-pressure sciences in molecular crystals and rare-earth metal hydrides, and bismuth alloys by means of synchrotron radiation x-ray powder diffraction, electrical resistivity measurement and spectroscopy.

In recent years, our group in Niigata Univ. has an interest in pressure-induced superconductivity observed in bismuth alloys such as A₂B₃-type topological compounds and Bi-Sb substitutional alloy. For example, a figure on the right side shows pressure dependences of crystal structure and electrical resistivity observed at room temperature and the superconducting transition temperatures (Tc) in bismuth telluride (Bi₂Te₃). We try to reveal the effect of pressure on the superconductivity of bismuth alloys from the relationship between transport properties and crystal structures.

In this project, I try to make clear the structural and superconducting properties of topological compounds at high pressures and low temperatures. Furthermore, I experimentally investigate pressure-induced topological transition in layered bismuth alloys reported by recent theoretical study. I'm looking forward to elucidating these phenomena in cooperation with other experimental and theoretical groups.