  By intercalation of alkaline-earth metal Sr in Bi2Se3, superconductivity with
large shielding volume fraction (~91.5% at 0.5 K) has been achieved in
Sr0.065Bi2Se3. The analysis of the Shubnikov-de Hass oscillations confirms the
1/2-shift expected from a Dirac spectrum, giving transport evidence of the
existence of surface states. Importantly, the SrxBi2Se3superconductor is stable
under air, making the SrxBi2Se3 compound an ideal material base for
investigating topological superconductivity.
