Yasushi IshiiYasushi Ishii has been working on quasicrystals since soon after the discovery of quasicrystals and contributing to developing new ideas on quasicrystals: TF are working on mainly electronic structures of quasiperiodic systems and real quasicrystallie materials and YI are working on "phason"-related instability of quasicrystals as well as electronic structures. Read More Read Less