Forcing a polymer out of a potential well

We consider the forced escape of a polymer out of a potential well. The process has two steps - crossing the activation barrier, and translocation of the chain over the barrier. We suggest that translocation occurs by the motion of a kink, whose shape and velocity change as more and more beads of the polymer have come out of the potential well. We find that for short polymers, the translocation time ttrans ∼ ln(n0), where n0 is the number of beads that have crossed the barrier. For long chains, the translocation time ∼N, the total number of beads. © 2002 Elsevier Science B.V. All rights reserved.