Collaborative effects in polymer translocation and the appearance of fictitious free-energy barriers

The translocation time of a polymer through a pore under the influence of an external field depends on a number of parameters, the most important of which are the field strength, the interaction with the pore, and the confinement entropy. Experimentally, the translocation is dominated either by the driving force (electrophoretic regime) or by the entropy of confinement or pore interaction (barrier dominated regime). In this Rapid Communication we study a simple model for polymer translocation, loosely based on the asymmetric exclusion process, which shows that it is possible to have what experimentally would be interpreted as barrier dominated, even where there is no barrier to translocation. This effective barrier is interpreted as being due to collaborative effects between the monomers forming the polymer chain.