SELF-DIFFUSION IN RANDOM-TILING QUASI-CRYSTALS

The first explicit realization of the conjecture that phason dynamics leads to self-diffusion in quasicrystals is presented for the icosahed ral Ammann tilings. On short time scales, the transport is found to be subdiffusive with the exponent beta approximate to 0.57(1), while on long time scales it is consistent with normal diffusion that is up to an order of magnitude larger than in the typical room temperature vaca ncy-assisted self-diffusion. No simple finite-size scaling is found, s uggesting anomalous corrections to normal diffusion, or existence of a t least two independent length scales. A connection with transport in membranes is also noted.