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Order of the phase transition in models of DNA thermal denaturation

Nikos Theodorakopoulos·Thierry Dauxois·Michel Peyrard
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Abstract

We examine the behavior of a model which describes the melting of double-stranded DNA chains. The model, with displacement-dependent stiffness constants and a Morse on-site potential, is analyzed numerically; depending on the stiffness parameter, it is shown to have either (i) a second-order transition with "nu_perpendicular" = - beta = 1, "nu_parallel" = gamma/2 = 2 (characteristic of short range attractive part of the Morse potential) or (ii) a first-order transition with finite melting entropy, discontinuous fraction of bound pairs, divergent correlation lengths, and critical exponents "nu_perpendicular" = - beta = 1/2, "nu_parallel" = gamma/2 = 1.

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Nikos Theodorakopoulos, Thierry Dauxois, Michel Peyrard. 2000-04-29. Order of the phase transition in models of DNA thermal denaturation. https://doi.org/10.1103/physrevlett.85.6

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