Thermal conductivity and critical modes in one-dimensional Fibonacci quasicrystals

We consider a general Fibonacci harmonic lattice in which both the masses a nd the elastic constants are aperiodically arranged. Making use of a suitab le decimation scheme, inspired in real-space renormalization group concepts , we obtain closed analytical expressions for the global transfer matrix an d transmission coefficient for several resonant critical normal modes. The fractal structure of the frequency spectrum has a significant influence in the cumulative contribution of the different normal modes to the thermal tr ansport. A sudden enhancement of the thermal coefficient around a set of sp ecial frequencies indicates the importance of resonance effects in the ther mal conductivity of Fibonacci quasicrystals. (C) 2000 Elsevier Science B.V. All rights reserved.