Proximity Induced Superconductivity in Antimony Telluride Single Crystal by an Interplay of Indium contacts

To investigate the proximity and inverse proximity superconductivity (SC) in topological materials (TMs) {such as topological insulators (TIs) and topological crystalline insulators (TCIs)} by the hosting of an interface between TM/SC may be the novel strategy in the understanding of the unexplored Majorana fermions and spin-triplet superconductivity etc. [https://doi.org/10.1103/PhysRevB.81.241310, https://doi.org/10.1103/PhysRevRes.3.033008]. The TMs are known to preserve the non-trivial surface states (SS) which have emerged for exploring the exotic superconducting properties induced by the proximity effect. The observed superconductivity (proximity & inverse proximity) induced due to the mutual competition between the robust SS of TMs and sub energy gap of SCs. This strong competition between the electron-electron interaction (EEI) and cooper pairs correlation lead to proximity (inverse proximity) superconductivity if SC energy gap is dominant over EEI or vice versa (if rapidly mobile Dirac electrons break the phase coherence of cooper pairs at the interface (EEI>SC gap)) as discussed in this article. The subsequent changes discussed in the superconducting proximity with perpendicular and parallel magnetic field (M.F) makes this work very interesting due to the field dependence mechanism. The superconducting onset temperature is found to be (T _c ^onset ) ~4.1 K with the upper critical field (H _c2 ) ~1541 Oersted which is accordance with Ginzburg Landau Theory (GLT) observed in Sb ₂ Te ₃ contacted with s-wave SC indium.