The configuration of a topological current and physical structure: an   application and paradigmatic evidence
  In the $\phi $-mapping theory, the topological current constructed by the order parameters can possess different inner structure. The difference in topology must correspond to the difference in physical structure. The transition between different structures happens at the bifurcation point of the topological current. In a self-interaction two-level system, the change of topological particles corresponds to change of energy levels. 
Li-Bin Fu, Jie Liu, Shi-Gang Chen, and Yi-Shi Duan