Unbinding of mutually avoiding random walks and two-dimensional quantum gravity.
We analyze the unbinding transition for a two-dimensional lattice polymer in which the constituent strands are mutually avoiding random walks. At low temperatures the strands are bound and form a single self-avoiding walk. We show that unbinding in this model is a strong first order transition. The entropic exponents associated with denaturated loops and end-segment distributions show sharp differences at the transition point and in the high temperature phase. Their values can be deduced from some exact arguments relying on a conformal mapping of copolymer networks into a fluctuating geometry, i.e., in the presence of quantum gravity. An excellent agreement between analytical and numerical estimates is observed for all cases analyzed.
Carlon
Enrico
E
Interdisciplinary Research Institute c/o IEMN, Cité Scientifique, Boîte Postale 69, F-59652 Villeneuve d'Ascq, France.
Baiesi
Marco
M