Conductivity of Quasiperiodic Systems: A Numerical Study

We develop a new real-space method which allows one to evaluate the Kubo-Greenwood formula for dc conductivity of independent electrons in a static potential. We apply it to a numerical study of propagation modes in three dimensional quasiperiodic systems. These modes are strikingly different from those of periodic ones with regard to the effect of disorder. In particular, for Fermi energies in pseudogaps the conductivity can be stable or can even increase when disorder increases.