Field-induced winding of chiral polymers

Abstract:

We propose a microscopic model of a chiral polymer chain with permanent transverse dipoles interacting with an external electric field. Its behaviour has been investigated by computer simulation in the limit of weak chirality. Large-scale (tertiary) helical winding induced along the field direction has been found above a threshold field E_c, and the helix parameters have been calculated as functions of the field strength. Below E_c there is no coherent helical structure of the chain conformation. We find a characteristic scaling of the threshold and the winding radius a with the chain bending modulus $\varepsilon ,({E_c}/{k_B}T) \sim {\varepsilon ^{1/4}}$and $a \sim ({k_B}T/E)\varepsilon$.