ARPES measurements of the topological insulator, Bi2Se3, and Ga/Cu-doped Bi2Se3

Topological insulators (TIs) possess surface states and high mobility, due to the presence of strong spin-orbit coupling and time-reversal symmetry (TRS). Bi2Se3 is one of the most promising TI due to its relatively large bandgap (0.3 eV), making it the most suitable to work at room temperature. The bulk of Bi2Se3 tends to become n-type degenerate moving the chemical potential toward the conduction band. Though by doping, it is possible to move the chemical potential into the bandgap within the surface states. We use a molecular beam epitaxy (MBE) to grow high-quality single-crystal thin films of Bi2Se3 and gallium and copper-doped Bi2Se3. The addition of gallium and copper leads to an expansion of the crystal lattice and the formation of extra conductive channels. There is a possibility of topological superconductivity (TS) by doping with Ga and Cu. By performing ARPES measurements, we will be able to obtain detailed electronic band structure, providing fundamental knowledge of the doping influence at the surface states and the Fermi Surface of the topological insulator.