Signature of proximity-induced px + ipy triplet pairing in the doped topological insulator Bi2Se3 by the s-wave superconductor NbN
1 Physics Department, Technion - Israel Institute of Technology - Haifa 32000, Israel
2 Racah Institute of Physics and the Hebrew University Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem - Jerusalem 91904, Israel
Received: 22 August 2013
Accepted: 23 September 2013
In the search for Majorana fermions in proximity-induced topological superconducting junctions, we happened to find a signature of same-spin triplet superconductivity which appears to dominate these elusive elementary excitations. Thin-film junctions and bilayers of the doped topological insulator and the s-wave superconductor NbN exhibit conductance spectra with coexisting prominent zero-bias and coherence peaks. Various tunneling models with different pair potentials have failed to fit our data, except for the triplet pair potential, which breaks time-reversal symmetry, that yielded reasonably good fits. This provides supporting evidence for proximity-induced triplet superconductivity in the layer near the interface with the NbN film.
PACS: 74.45.+c – Proximity effects; Andreev reflection; SN and SNS junctions / 74.20.Rp – Pairing symmetries (other than s-wave) / 73.20.-r – Electron states at surfaces and interfaces
© EPLA, 2013