While a linear disordered system shows energy localisation (Anderson localisation), it has been numerically observed that, an extra nonlinear term in the equation causes a wavepacket to spread apparently indefinitely. We study nonlinear chains with disorder and seek to understand the nature of the solutions of the nonlinear system. [PRL, 2008] [PRE, 2009]
Charge transfer in DNA is of great biological importance because of the role that it can play in damage occurring under conditions of oxidative stress. We have investigated propagation of a charge carrier along intrinsically dynamically disordered double-stranded DNA. This is realized by the semiclassical coupling of the charge with a nonlinear lattice model that can describe large amplitude fluctuations of the base pairs leading to the thermal denaturation transition of DNA. We found that the fluctuating intrinsic disorder can trap the charge and inhibit polaronic charge transport. [PRE, 2002]