Quantum percolation of one-electron states in power-law diluted chains

• Main Author: Silva Jr.,M. P. da
• Publication Date: 2008
• Other Authors: Albuquerque,S. S., Moura,F. A. B. F. de, Lyra,M. L.
• Format: Article
• Language: eng
• Source: Brazilian Journal of Physics
• Download full: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-97332008000100008
• topic: Quantum percolation; Anderson localization; Long-range couplings

We investigate the nature of one-electron eigenstates in power-law diluted chains for which the probability of occurrence of a bond between sites separated by a distance r decays as p(r) = 1/r1+sigma. Using an exact diagonalization scheme on finite chains, we compute the spreading of an initially localized wave-packet, the time dependent participation number as well as the return probability. Our results show the existence of a phase of extended states. By considering the scale invariance of the fluctuations of the participation number at the Anderson transition, we obtained that extended states emerges for sigma < 0.68. This limiting value is larger than the one reported in the literature for the emergence of extended states in one-dimensional Anderson models with power-law decaying couplings.