Superconducting features at Bi-Sb twisting crystallite interfaces

Abstract

We present the results of the study of quantum oscillations, magnetic and superconducting properties of the twisting bicrystals of 3D topological insulator Bi1-xSbx (0.07 < x < 0.15) at low temperatures and in magnetic fields up to 400 kOe.It has been found that the small crystallite disorientation angle (SDA) interfaces, which consist of a solitary central part ( thickness of about 60 nm) and two similaradjacent layers (~20 nm) on both sides of it, exhibit two superconducting transitions with critical temperature Tc~ (3.7 - 4.6)K and Tc~ (8.3 – 21)K.