The search for an unusual form of superconductivity known as topological superconductivity has attracted a great deal of attention of the quantum materials community because of its fundamental novelty and potential applications in fault-tolerant quantum computing technology. A hybrid structure of a topological insulator and an s-wave superconductor is expected to host topological superconductivity. A thin-film material platform is particularly useful in building devices and device applications.

An IRG team has developed a new synthetic approach to overcome prior growth challenges to realize a thin-film topological insulator/superconductor hybrid structure. This approach produced high-quality epitaxial (Bi,Sb)2Te3/graphene/two-atomic-layer gallium heterostructures with atomically abrupt interfaces that shows robust proximity-induced superconductivity in the Dirac surface states of the (Bi,Sb)2Te3film, thus fulfilling a necessary step to the creation of a topological superconductor. This work paves the path to explorations of topological superconductivity and quantum computing circuitry in a scalable material platform.