An Efficient Dopant for Introducing Magnetism into Topological Insulator Bi(2)Se(3)

In this work, we obtained an effective way to introduce magnetism into topological insulators, and successfully fabricated single crystal C-Bi(2)Se(3). The structural, electrical and magnetic properties of non-magnetic element X (B, C and N) doped at Bi, Se1, Se2 and VDW gap sites of Bi(2)Se(3) were studied by the first principles. It is shown that the impurity bands formed inside the bulk inverted energy gap near the Fermi level with C doping Bi(2)Se(3). Due to spin-polarized ferromagnetic coupling, the time inversion symmetry of Bi(2)Se(3) is destroyed. Remarkably, C is the most effective dopant because of the magnetic moment produced by doping at all positions. The experiment confirmed that the remnant ferromagnetism Mr is related to the C concentration. Theoretical calculations and experiments confirmed that carbon-doped Bi(2)Se(3) is ferromagnetic, which provides a plan for manipulating topological properties and exploring spintronic applications.