Macroscopic Charged Heterotic String
  Classical solutions of equations of motion in low energy effective field theory, describing fundamental charged heterotic string, are found. These solutions automatically carry an electric current equal to the charge per unit length, and hence are accompanied by both, electric and magnetic fields. Force between two parallel strings vanish due to cancellation between electric and magnetic forces, and also between graviton, dilaton, and antisymmetric tensor field induced forces. Multi-string solutions describing configuration of parallel strings are also found. Finally, the solutions are shown to possess partially broken space-time supersymmetry. 
Ashoke Sen