SCALING OF FLUCTUATION FOR DIRECTED POLYMERS WITH RANDOM INTERACTION

Using a finite size scaling form for reunion probability, we show nume rically the existence of a binding-unbinding transition for directed p olymers with random interaction. The cases studied are (A1) two chains in 1 + 1 dimensions, (A2) two chains in 2 + 1 dimensions and (B) thre e chains in 1 + 1 dimensions. A similar finite size scaling form for f luctuation establishes a disorder-induced transition with identical ex ponents for cases A2 and B. The length scale exponents in all the thre e cases are in agreement with previous exact renormalization-group res ults.