1? x Sb x (0.07 x 0.2)]]>

摘要

Abstract In the normal state the 3D topological insulator Bi1? x Sb x is diamagnetic and does not show superconductivity because of the extremely low carrier density. Despite this, we have found that the small crystallite disorientation angle (SDA) interfaces of bismuth-antimony bicrystals, which consist of a solitary central part (thickness of about 60 nm) and two similar adjacent layers (～20 nm) on both sides of it, exhibit two superconducting transitions with critical temperature T c ～ ( 3.7 – 4.6 ) ?K and T