Fine Structure In The Electronic Density Of States Near The Fermi Energy Of Al-ni-co Decagonal Quasicrystal From Ultrafast Time-resolved Optical Reflectivity

摘要

We measured the temperature and fluence dependence of the time-resolved photoinduced optical reflectivity in a decagonal Al_(71.9)Ni_(11.1)Co_(17.0) quasicrystal. We find no evidence for the relaxation of a hot thermalized electron gas as observed in metals. Instead, a quick diffusion of the hot nonthermal carriers ～40 nm into the bulk is detected, enhanced by the presence of a broad pseudogap. From the relaxation dynamics we find evidence for the suppression of the electronic density of states (DOS) at the Fermi energy with respect to the electronic DOS at ～13 meV away from the Fermi energy which is consistent with recent theoretical calculations.