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arXiv · 1801.03418

Like-charge attraction in a one-dimensional setting: the importance of being odd

E. Trizac·G. Téllez
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Abstract

From cement cohesion to DNA condensation, a proper statistical physics treatment of systems with long range forces is important for a number of applications in physics, chemistry, and biology. We compute here the effective force between fixed charged macromolecules, screened by oppositely charged mobile ions (counterions). We treat the problem in a one dimensional configuration, that allows for interesting discussion and derivation of exact results, remaining at a level of mathematical difficulty compatible with an undergraduate course. Emphasis is put on the counter-intuitive but fundamental phenomenon of like-charge attraction, that our treatment brings for the first time to the level of undergraduate teaching. The parity of the number of counterions is shown to play a prominent role, which sheds light on the binding mechanism at work when like-charge macromolecules do attract.

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E. Trizac, G. Téllez. 2018-01-05. Like-charge attraction in a one-dimensional setting: the importance of being odd. https://doi.org/10.1088/1361-6404/aa9e80

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