Suppression of Andreev conductance in a topological insulator

Suppression of Andreev conductance in a topological insulator–superconductor nanostep junction

Zheng Yi-Jie, Song Jun-Tao, Li Yu-Xian^†,

(a) Schematics of the N₁N₂S step junction, the region I is in the x–y plane, the region II y–z plane, and the superconductivity region III in x–y plane, respectively. (b) The energy dispersion in three regions, the propagating wave vector in regions I and III is k_x and in region II is k_z.