Interfacial Superconductivity and Zero Bias Peak in Quasi‐One‐Dimensional Bi ₂ Te ₃ /Fe _1+y Te Heterostructure Nanostructures

Bismuth telluride/iron telluride (Bi2Te3/Fe1+yTe) heterostructures are known to exhibit interfacial superconductivity between two non-superconducting materials: Fe1+yTe as the parent compound of Fe-based superconducting materials and topological insulator Bi2Te3. Here, a top-down approach is presented starting from 2D fabricate 1D Bi2Te3/Fe1+yTe nanowires or narrow nanoribbons. It demonstrated that heterostructure remains intact in nanostructures widths on order 100 nm preserved, evidenced by electrical transport Andreev reflection point contact spectroscopy experiments measured at end nanowire. The differential conductance shows similar twin-gap structure heterostructures, but with enhanced fluctuation effects due lower dimensionality. A zero-bias peak indicates presence an bound state and, given involvement Bi2Te3 surface state, possible nature discussed strong interplay emerging ferromagnetism interstitial excess iron (Fe) layer, developing parallel low temperatures.