Branching transition of a directed polymer in random medium
Dipartimento di Fisica and Sezione INFN, Università di Bologna, I-40126 Bologna, Italy
2 INFM-Dipartimento di Fisica and Sezione INFN, Università di Padova, I-35131 Padova, Italy
Accepted: 7 May 1997
A directed polymer is allowed to branch, with configurations determined by global energy optimization and disorder. A finite-size scaling analysis in 2D shows that, if disorder makes branching more and more favorable, a critical transition occurs from the linear scaling regime first studied by Huse and Henley (Phys. Rev. Lett., 54, (1985) 2708) to a fully branched, compact one. At criticality clear evidence is obtained that the polymer branches at all scales with dimension and roughness exponent satisfying , and energy fluctuation exponent , in terms of longitudinal distance.
PACS: 05.70.Jk – Critical point phenomena / 64.60.Ak – Renormalization-group, fractal, and percolation studies of phase transitions / 61.41.+e – Polymers, elastomers, and plastics
© EDP Sciences, 1997