On the Breathers of $a_n^{(1)}$ Affine Toda Field Theory
  Explicit constructions of $a_n^{(1)}$ affine Toda field theory breather solutions are presented. Breathers arise either from two solitons of the same species or from solitons which are anti-species of each other. In the first case, breathers carry topological charges. These topological charges lie in the tensor product representation of the fundamental representations associated with the topological charges of the constituent solitons. In the second case, breathers have zero topological charge. The breather masses are, as expected, less than the sum of the masses of the constituent solitons. 
U. Harder, A. Iskandar and W. McGhee