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DY: Dynamik und Statistische Physik
DY 46: Poster
DY 46.70: Poster
Donnerstag, 30. März 2006, 16:00–18:00, P1
Like-charged rods at zero temperature — •Axel Arnold1 and Christian Holm2 — 1FOM Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ Amsterdam, The Netherlands — 2Frankfurt Institute for Advanced Studies, Max von Laue-Str. 1, D-60438 Frankfurt a. M.
It is well known that charged polymers can attract in the presences of multivalent counterions. This effect has been confirmed by a large number of computer simulations, and experiments have shown that DNA, a stiff, highly negatively charged polyelectrolyte, can be condensed by multivalent counterions. This correlation–induced attraction is for instance believed to be important for the compaction of DNA inside viral capsids. Here the DNA is idealized as an infinitely long, charged rod.
We investigate the attraction of like–charged rods in the presence of counterions using the strong coupling theory of R. Netz. We present results for the equilibrium distance of the rods at infinite counterion–coupling and the particle distribution. These results are in good agreement with numerical simulations. Our results show that the degree of agreement between the simulations at finite coupling and the theory can be characterized by a single parameter γRB.
In the case of zero temperature, one finds under certain circumstances flat configurations, in which all charges are located in the rod–rod plane. The energetically optimal configuration and its stability are determined analytically, which depends on only one parameter γz, similar to γRB. These findings are in good agreement with results from computer simulations.