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HL: Fachverband Halbleiterphysik

HL 5: Topological insulators

HL 5.6: Vortrag

Montag, 1. April 2019, 10:45–11:00, H36

Superconductivity in MBE grown In_xSn_1−xTe/Bi₂Te₃ films — •Andrea Bliesener, Junya Feng, Alexey Taskin, and Yoichi Ando — Institute of Physics II, University of Cologne, Germany

In_xSn_1−xTe is derived from the topological crystalline insulator SnTe which becomes superconducting when doped with Indium and it is one of the top candidates for topological superconductivity [1].

In_xSn_1−xTe thin films have been grown by molecular beam epitaxy (MBE) on a Bi₂Te₃ buffer layer, which has a good lattice matching for the growth in the (111) direction [2]. Using in situ post-annealing procedures, we achieve robust superconductivity in the grown In_xSn_1−xTe films.

To look for possible signatures of topological superconductivity in the grown films, we fabricated tunnelling junctions on the surface of the superconducting In_xSn_1−xTe films. The tunnelling spectroscopy data shows a clear two-gap structure in the measured conductance spectra which points to the coexistence of bulk and surface superconductivity in the studied In_xSn_1−xTe thin films.

References

[1] S. Sasaki et al; Physical Review Letters 109, 217004 (2012)

[2] A. A. Taskin et al; Physical Review B 89, 121302(R) (2014)