Multifractal scaling of electronic transmission resonances in perfect and imperfect Fibonacci delta-function potentials

We present here a detailed multifractal scaling study for the electronic tr ansmission resonances with the system size for an infinitely large one-dime nsional perfect and imperfect quasiperiodic system represented by a sequenc e of delta-function potentials. The electronic transmission resonances in t he energy minibands manifest more and more fragmented nature of the transmi ttance with the change of system size. We claim that when a small perturbat ion is randomly present at a few number of sites or layers, the nature of e lectronic states will change and this can be understood by studying the ele ctronic transmittance with the change of system size. We report the differe nt critical states manifested in the size variation of the transmittance co rresponding to the resonant energies for both perfect and imperfect cases t hrough multifractal scaling study for few of these resonances. (C) 1999 Els evier Science B.V. All rights reserved.