Discrete charge patterns in a Holstein‐SSH DNA lattice |
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Authors: | Adamou Koko Dang Conrad Bertrand Tabi Henri Paul Ekobena Fouda Timoleon Crepin Kofané |
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Institution: | 1. Laboratory of Biophysics, Department of Physics, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon;2. Theoretical Physics Group, Department of Physics, Faculty of Science, University of Stellenbosch, Private Bag X1 Matieland, Stellenbosch, South Africa;3. The African Institute for Mathematical Sciences, Muizenberg, South Africa;4. Laboratory of Mechanics, Department of Physics, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon |
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Abstract: | DNA nonlinear charge transport is addressed in a combined Holstein–Su–Schrieffer–Heeger (HSSH) model. In the adiabatic approximation the dynamics of the system is shown to be governed by a modified discrete nonlinear Schrödinger (MDNLS) equation, where charge‐lattice coupling parameters are obvious. Attention is paid to the effective coupling parameter, , between charge and internal molecular vibrations, which importantly influences the stability/instability features of the plane wave, solution to the MDNLS equation. Region of instability are remarkably reduced, therefore predicting that increasing could progressively quench charge transport. This is confirmed by numerical simulations on the generic HSSH model, where only the charge density is excited and drives the dynamics of the global system. Polarons, as well as longitudinal and transversal nonlinear waves, are obtained and the dependence of charge transport on DNA conformation is discussed. Accordingly, the longtime evolution of the found polarons is studied and we observe a progressive extinction of its temporal evolution as increases. © 2014 Wiley Periodicals, Inc. |
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Keywords: | charge transport polarons solitons DNA |
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