Magnetoresitance vs. electronic structure in Cu doped single crystalline Bi2Se3 3D topological insulator

Bismuth selenide (Bi₂Se₃) is one of the 3D topological insulators (TI) that can be characterised as materials of a semiconducting volume and a conductive surface. The evolution of the electronic structure of (Bi_1−xCu_x)₂Se₃ (x = 0, 0.025, 0.05, 0.09 and 0.125) was investigated by angle-resolved photoemission spectroscopy (ARPES), scanning tunnelling microscopy (STM/STS) and Shubnikov-de Haas oscillations (SdH). The results show that doping with Cu does not change the electronic structure, in particular it does not destroy the nontrivial topology of the system. The lack of superconductivity is discussed in view of intercalated Cu_xBi₂Se₃ in which superconductivity is observed.