The successful candidate (postdoctoral fellow) is a young researcher who is expected to lead quantum beam sciences or take a pivotal role in the IMSS's quantum-beam facilities in the future. The applicants of all research areas, who can collaborate with the IMSS tsukuba-campus staffs, are welcome; the research areas include solid state physics with XRD, materials science with XAFS, surface science with positron diffraction , exploratory studies towards future light source, development of detector system , life science with cryo-EM, and more. We encourage the applicants to provide the name of one or a couple of IMSS staffs who may collaborate with them. (The committee may ask the staff(s) for opinion.)