Numerical evidence of backscattering in approximants of quasicrystals

Abstract

We compute the velocity correlation function of electronic states close to the Fermi energy, in approximants of quasicrystals. As we show, the long time value of this correlation function is small. This means a small Fermi velocity, in agreement with previous band structure studies. Furthermore, the correlation function is negative on a large time interval, which means a phenomenon of backscattering. As shown in previous studies, the backscattering can explain unusual conduction properties observed in these alloys, such as the increase of conductivity with disorder.