Effects of the electronic structure on the dc conductance of Fibonacci superlattices

Abstract

We derive a discrete Hamiltonian describing a Fibonacci superlattice in which the electronic potential is taken to be an array of equally spaced delta potentials, whose strengths modulate the chemical composition in the growth direction. In this model both diagonal and off-diagonal elements of the Hamiltonian matrix become mutually related through the potential strengths. The corresponding energy spectrum and related magnitudes, such as the Lyapunov coefficient, transmission coefficient, and Landauer resistance, exhibit a highly fragmented, self-similar nature. We investigate the influence of the underlying spectrum structure on the dc conductance at different temperatures obtaining analytical expressions which relate special features of the dc conductance with certain parameters that characterize the electronic spectrum of Fibonacci superlattices.