Topological Insulators are a class of materials which is insulating in the bulk, but conducting on the surface. The symmetry protected surface states allows spin-polarised conduction along specific channels, which are of huge interest for spintronics, quantum computation, Majorana particles, quantum anomalous hall effect etc. Some of the well-known topological insulators are Bi2Te3, Sb2Te3 and the band structures are shown beloew. Further updates will be available soon.

References:

• Colloquium: Topological insulators, M. Z. Hasan and C. L. Kane, Rev. Mod. Phys. 82, 3045

• Experimental Observation of the Quantum Anomalous Hall Effect in a Magnetic Topological Insulator, Science, Vol. 340, 6129, 167-170 (2013)

• Kou, Liangzhi, Yandong Ma, Ziqi Sun, Thomas Heine, and Changfeng Chen. "Two-dimensional topological insulators: Progress and prospects." The journal of physical chemistry letters 8, no. 8 (2017): 1905-1919.