Recently, Nb-doping of topological insulator Bi2Se3 has attracted much attention as a way to pursue topological superconductivity. Here, in contrast to previous reports, superconductivity in NbxBi2Se3 is found to arise from the misfit phase (BiSe)1.10NbSe2 and not from Nb intercalation into Bi2Se3.
Misfit phase (BiSe)1.10NbSe2 as the origin of superconductivity in niobium-doped bismuth selenide