Superconductivity with Topological Surface State in Sr_<i>x</i>Bi₂Se₃

Abstract

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. Analysis of the Shubnikov-de Hass oscillations confirms the half-shift expected from a Dirac spectrum, giving transport evidence of the existence of surface states. Importantly, SrxBi2Se3 superconductor is stable under air, making SrxBi2Se3 an ideal material base for investigating topological superconductivity.