Hui Xu

RENORMALIZATION SCHEME TO THE CHARGE TRANSFER EFFICIENCY OF SINGLE-STRAND DNA WITH LONG RANGE CORRELATED DISORDER

By using a renormalization group method together with a minimum set of parameters, the charge transfer efficiency of single-stranded synthetic guanine–cytosine DNA sequence with long-range correlated disorder is investigated. Numerical results for the transmission coefficient are derived and compared with those corresponding to periodic poly(GC) sequence. We find that, when the correlation exponent arrives at its critical value, new long-range correlations induced electronic states are formed within the energy gap between the guanine highest-occupied molecular orbital and cytosine lowest-unoccupied molecular orbital, and these two bands emerged into one at which transmission is ballistic. At the same time, a series of high-conductance peaks which indicate the existence of extended states appeared, revealing a presence of localization–delocalization phase transition in this gap. We also find that the transmission spectra are stable for all the correlation exponents which are greater than the critical one, ...

LYAPUNOV EXPONENT AND THE LOCALIZED PROPERTIES OF ELECTRONIC STATES OF ONE-DIMENSIONAL DISORDERED BINARY ALLOY

Based on the tight-binding model of the single electron, the one-dimensional Anderson model with random binary distributed on-site energies is studied using the transfer-matrix approach. We calculate numerically the localization length, the density of the electronic states and the Lyapunov exponent. The results show that the localization length strongly depends on energies and is affected by disordered degrees to some extent. With finite size systems, the localization length presents obvious effect on the impurity concentration. While in the dilute limit there exist extended states, increasing the impurity concentration beyond a critical value destroys these extended states and the localization length over the entire energy range becomes smaller than the system size. By studying the scaling relation, we find that the localized states are stable in the thermodynamic limit. Transforming the random matrix product into a conformal map, we introduce the Lyapunov exponent, which is finite within the entire band...