Control of electron transfer in disordered DNA under the impact of viscous damping and an external periodic field
Freie Universität Berlin, Fachbereich Physik, Institut für Theoretische Physik,
Arnimallee 14, 14195 Berlin, Germany
Corresponding author: a email@example.com
Published online: 29 November 2002
We investigate the influence of energetic disorder, viscous damping and an external field on the electron transfer (ET) in DNA. The double helix structure of the λ-form of DNA is modeled by a steric oscillator network. In the context of the base-pair picture two different kinds of modes representing twist motions of the base pairs and H-bond distortions are coupled to the electron amplitude. Through the nonlinear interaction between the electronic and the vibrational degrees of freedom localized stationary states in the form of standing electron-vibron breathers are produced which we derive with a stationary map method. We show that in the presence of additional energetic disorder the degree of localization of such breathers is enhanced. It is demonstrated how an applied electric field initiates the long-range coherent motion of breathers along the bases of a DNA strand. These moving electron-vibron breathers, absorbing energy from the applied field, sustain energetic losses due to the viscous friction caused by the aqueous solvent as well as the impact of a moderate amount of energetic disorder. Moreover, it is illustrated that with the choice of the amplitude and frequency of the external field, the breather can be steered to a desired lattice position achieving control of the ET.
PACS: 87.15.-v – Biomolecules: structure and physical properties / 63.20.Kr – Phonon-electron and phonon-phonon interactions / 63.20.Ry – Anharmonic lattice modes
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2002