By using topological current theory, this paper studies the inner topological structure of disclinations during the melting of two-dimensional systems. From two-dimensional elasticity theory, it finds that there were topological currents for topological defects in homogeneous equation. The evolution of disclinations was studied, and the branch conditions for generating, annihilating, crossing, splitting and merging of disclinations were given.

Topological Aspect of Disclinations in Two-Dimensional Crystals. W.K.Qi, T.Zhu, Y.Chen, J.R.Ren: Chinese Physics B, 2009, 18[3], 1002