Electrical transport study of Bi$_{2}$Se$_{3}$ surface states

We report an electrical transport study of the topological insulator Bi$_{2}$Se$_{3}$ Topological insulators are materials characterized by a gap in the bulk and gapless surface states. The surface states have Dirac dispersions and are protected from back-scattering. The latter protection arises from the fundamental symmetries of the material, and has far reaching consequences for the generation of novel quantum states. We fabricate Bi$_{2}$Se$_{3}$ devices by mechanical exfoliation of 30-80nm thick flakes and standard electron-beam lithography. The devices are investigated using temperature dependence and magnetoresistance.