Localization of Electronic States in Chain Model Based on Real DNA Sequence

Hiroaki Yamada

Published 2004-06-02, updated 2004-07-07Version 2

We investigate the localization property of an electron in the disordered two-chain system (ladder model) with long-range correlation as a simple model for electronic property in DNA sequence. The chains are constructed by repetition of the sugar-phosphate sites, and the inter-chain hopping at the sugar sites come from nucleotide pairs, i.e., $A-T$ or $G-C$ pairs. It has been found that some DNA sequences have long-range correlation. In this paper we use some actual DNA sequences such as bacteriophages of escherichia coli, human omosome 22 and histone protein as the correlated sequence for the interchain hopping at the sugar sites. We will present some numerical results for the Lyapunov exponent (inverse localization length) of the wave function in the cases in comparison to the results for artificial sequence generated by an asymmetric modified Bernoulli map. It is shown that the correlation and asymmetry of the sequence affect on the localization in both the artificial and real DNA sequences.