Two-dimensional superconductivity realized in an MBE-grown Bi2Te3/FeTe heterostructure

We report a superconductivity realized at the interface of a Bi2Te3/FeTe heterostructure fabricated via van der Waals epitaxy using the molecular beam epitaxy technique, which appears even when the thickness of Bi2Te3 is as thin as one quintuple layer. The two-dimensional nature of the observed superconductivity with the highest transition temperature around 12 K was verified by the existence of a Berezinsky-Kosterlitz-Thouless transition and the diverging ratio of in-plane to out-plane upper critical field on approaching the superconducting transition temperature. The underlying mechanism of this interfacial superconductivity will be discussed. The heterostructure studied in this work provides an ideal platform with unconventional superconductivity for hosting Majorana fermions and studying their exotic physics