  We study the quantum diffusion of charge carriers in octagonal tilings. Our
numerical results show a power law decay of the wave-packet spreading, $L(t)
\propto t^{\beta}$, characteristic of critical states in quasicrystals at large
time $t$. For many energies states are sub-diffusive, i.e. $\beta < 0.5$, and
thus conductivity increases when the amount of defects (static defects and/or
temperature) increases.
