Abstract The spin-dependent Andreev reflection is investigated theoretically by analyzing the electronic transport in a thin-film topological insulator (TI) ferromagnet/superconductor (FM/SC) junction. The tunneling conductance and shot noise are calculated based on the Dirac-Bogoliubov-de Gennes equation and Blonder-Tinkham-Klapwijk theory. It is found that the magnetic gap in ferromagnet can enhance the Andreev retro-reflection but suppress the specular Andreev reflection. The gate potential applied to the electrode on top of superconductor can enhance the two types of reflections. There is a transition between the two types of reflections at which both the tunneling conductance and differential shot noise become zero. These results provide a method to realize and detect experimentally the intra-band specular Andreev reflection in thin film TI-based FM/SC structures.
(Proximity effects; Andreev reflection; SN and SNS junctions)
Corresponding Authors:
Hong Li
E-mail: lihong302@upc.edu.cn
Cite this article:
Hong Li(李红) and Xin-Jian Yang(杨新建) Spin transport properties in ferromagnet/superconductor junctions on topological insulator 2022 Chin. Phys. B 31 127301
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