Berlin 2005 – wissenschaftliches Programm

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DY: Dynamik und Statistische Physik

DY 21: Statistical Physics in Biological Systems

DY 21.2: Vortrag

Samstag, 5. März 2005, 08:45–09:00, TU H2032

Breather induced anomalous charge diffusion in a DNA model — •George Kalosakas¹, Kia Ngai², and Sergej Flach¹ — ¹Max Planck Institute for the Physics of Complex Systems, Nothnitzer Str. 38, Dresden, 01187, Germany — ²Naval Research Laboratory, Washington DC, 20375-5320, USA

We present results on the diffusive motion of a charge along a double stranded DNA, which interacts with the nonlinear opening dynamics of base pairs. Signatures of anomalous diffusive properties are found at relatively high temperatures. A sublinear diffusion and a plateau appears before the standard long-time diffusion during the evolution of the mean squared displacement and a significant degree of heterogeneity is exhibited among individual trajectories. Both properties are connected with the existence of vibrational hot-spots (breather or multibreather excitations). Transport parameters of the charge are strongly affected in this case, as can be exemplified by the significant suppression of the diffusion coefficient D. The variation of D with temperature follows a stretched exponential law. The results are contrasted with those of the linearized case, in the absence of breathers.