  We explore the transport features of a single flexible polymer chain that
walks on a periodic ratchet potential coupled with spatially varying
temperature. At steady state the polymer exhibits a fast unidirectional motion
where the intensity of its current rectification depends strongly on its
elastic strength and size. Analytic and numerical analysis reveal that the
steady state transport of the polymer can be controlled by attenuating the
strength of the elastic constant. Furthermore, the stall force at which the
chain current vanishes is independent of the chain length and coupling
strength. Far from the stall force the mobility of the chain is strongly
dependent on its size and flexibility. These findings show how the mobility of
a polymer can be controlled by tuning system parameters, and may have novel
applications for polymer transport and sorting of multicomponent systems based
on their dominant parameters.
