Ultrafast filling of an electronic pseudogap in an incommensurate crystal

作者：Brouet V^*; Mauchain J; Papalazarou E; Faure J; Marsi M; Lin P H; Taleb Ibrahimi A; Le Fevre P; Bertran F; Cario L; Janod E; Corraze B; Phuoc V Ta; Perfetti L

来源：Physical Review B, 2013, 87(4): 041106.

DOI：10.1103/PhysRevB.87.041106

We investigate the quasiperiodic crystal (LaS)(1.196)VS2 by angle and time resolved photoemission spectroscopy. The dispersion of electronic states is in qualitative agreement with the band structure calculated for the VS2 slab without incommensurate distortion. Nonetheless, the spectra display a temperature dependent pseudogap instead of quasiparticle crossing. The sudden photoexcitation at 50 K induces a partial filling of the electronic pseudogap within less than 80 fs. The electronic energy flows into the lattice modes on a comparable time scale. We attribute this surprisingly short time scale to a very strong electron-phonon coupling to the incommensurate distortion. This result sheds light on the electronic localization arising in aperiodic structures and quasicrystals. DOI: 10.1103/PhysRevB.87.041106

• 出版日期2013-1-28
• 单位中国地震局