Directed polymer in random media with a defect.
We investigate a directed polymer in random media with an attractive defect at the center of the one-dimensional substrate. Without the defect, the end to end distance Deltax of the polymer follows Deltax approximately t;{1/z} , with z=3/2 and t is the polymer length. When the defect strength is weak, its contribution to Deltax is negligible. If > or =_{c} , then Deltax approaches a finite value Deltax_{sat}() in large t limit, and we find Deltax_{sat} approximately (-_{c});{-delta} , with delta approximately 3.0 . Such transition is related to the queuing phenomena of the asymmetric simple exclusion process. The polymer energy fluctuation is also discussed.
Lee
Jae Hwan
JH
Department of Physics, Soongsil University, Seoul 156-743, Korea.
Kim
Jin Min
JM