Plectoneme creation reduces the rotational friction of a polymer

The torsional dynamics of a semiflexible polymer with a contour length L larger than its persistence length L(p) that is rotated at fixed frequency omega(0) at one end is studied by scaling arguments and hydrodynamic simulations. We find a non-equilibrium transition at a critical frequency omega(*): In the linear regime, omega(0) < omega(*), axial spinning is the dominant dissipation mode. In the non-linear regime, omega(0) > omega(*), the twist dissipation mode involves the continuous creation of plectonemes close to the driven end and the rotational friction is substantially reduced. Copyright (C) EPLA, 2009