Potential Fu-Kane Topological Superconductor Island in Bi₂Te₃/VSi_x/Si Nanostructure

Topological superconductor islands are thought to be the building blocks of topological quantum bits. We produced single-crystalline VSi_x islands with well-defined side facets and island size more than 200 nm using molecular beam epitaxy on Si substrate heated to 950 ^\circC throughout the growth process. By means of scanning tunneling spectroscopy, we revealed dynamical Coulomb blockade and superconductivity on isolated islands and on islands being connected by superconducting wetting layer respectively. Bi_2Te_3 films were further deposited on VSi_x islands. Robust and homogenous proximity effect induced superconductivity was observed on various facets of the Bi_2Te_3/VSi_x hetero-nanostructure. Furthermore, our high-resolution spectroscopy identified Bosonic mode excitations on the topological superconductor islands. These results may establish a playground for the vortex Majorana islands.