| Autor: |
Granstrom, C. R., Fridman, I., Lei, H. -C., Petrovic, C., Wei, J. Y. T. |
| Rok vydání: |
2017 |
| Předmět: |
|
| Druh dokumentu: |
Working Paper |
| Popis: |
Using Andreev reflection (AR) as an experimental gauge of the superconducting proximity effect (PE), we assess the topological purity of the superconductivity that is induced by the c-axis PE between an s-wave superconductor and the topological insulators Bi$_{2}$X$_{3}$ (X=Se,Te). Point-contact AR spectroscopy is performed with Nb tips on Bi$_{2}$X$_{3}$ single crystals at 4.2 K. Scanning tunneling spectroscopy is also used, to locate the Fermi level $E_F$ relative to the Dirac point in the crystals. The AR data is analyzed with Blonder-Tinkham-Klapwijk theory, taking into account tip-induced spin-orbit coupling, Fermi-surface mismatch, and the co-presence of bulk band and topological surface states at $E_F$. Our results indicate that the superconductivity that can be proximity-induced into Bi$_{2}$X$_{3}$ is predominantly non-topological. |
| Databáze: |
arXiv |
| Externí odkaz: |
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