  We analyze the interaction of two conducting, charged polymer chains in
solution using a minimal model for their electronic degrees of freedom. We show
that a crossing of the two chains in which the polymers pass within Angstroms
of each other leads to a decrease of the electronic energy of the combined
system that is significantly larger than the thermal energy and thus promotes
interchain aggregation. We consider the competition of this attractive
interaction with the screened electrostatic repulsion and thereby propose a
phase diagram for such polymers in solution; depending on the charge density
and persistence length of the chains, the polymers may be unbound, bound in
loose, braid-like structures, or tightly bound in a parallel configuration.
