POLYMERS IN QUENCHED RANDOM ENVIRONMENT - WEAK REPLICA SYMMETRY-BREAKING

The case of polymers in strong quenched disorder is investigated. The disorder is modeled by a quenched random potential which is sampled by a flexible polymer chain. It is shown that the problem, originally fo rmulated in terms of Edwards type path integrals, can be transformed i nto an effective field theory. Localized phases of the polymer, where the size of the chain is independent of its contour length, i.e. (R(2) ) over bar alpha(1/Delta)(2/(4-d)), can be found by a weak breaking of the replica symmetry. Delta is a measure for the disorder. The same f ormalism predicts at d=4 an essential singularity (R(2)) over bar alph a exp(2 pi(2)/Delta) for vanishing disorder Delta-->0.