1301.1618 (Yunyou Yang et al.)

Topological phase transitions with and without energy gap closing    [PDF]

Yunyou Yang, Huichao Li, L. Sheng, R. Shen, D. N. Sheng, D. Y. Xing

Topological phase transitions in a three-dimensional (3D) topological insulator (TI) with an exchange field of strength $g$ are studied by calculating spin Chern numbers $C^\pm(k_z)$ with momentum $k_z$ as a parameter. When $|g|$ exceeds a critical value $g_c$, a transition of the 3D TI into a Weyl semimetal occurs, where two Weyl points appear as critical points separating $k_z$ regions with different first Chern numbers. For $|g|View original: http://arxiv.org/abs/1301.1618