Electronic Structure,Irreversibility Line and Magnetoresistance of Cu_0.3Bi₂Se₃ Superconductor

【摘要】 Cu_xBi2Se3 is a superconductor that is a potential candidate for topological supercoDducton We report our laserbased angle-resolved photoemission measurement on the electronic structure of the Cu_xBi2Se3 superconductor, and a detailed magneto-resistance measurement in both normal and superconducting states. We iiiid that the topological surface state of the pristine Bi2Se3 topological insulator remains robust after the Cu-intercalation,while the Dirac cone location moves downward due to electron doping. Detailed measurement on the magnetic field-dependence of the resistance in the superconducting state establishes an irreversibility line and gives a value of the upper critical field at zero temperature of ⁴000 Oe for the Cu_xBi2Se3 superconductor with a middle point Tc of 1.9 K. The relation between the upper critical Geld H_C2 and temperature T is dilFerent from the usual scaling relation found in cuprates and in other kinds of superconductors. Small positive magneto-resistance is observed in Cu_xBi2Se3 superconductors up to room temperature. These observations provide useful information for further study of this possible candidate for topological superconductors.更多还原

【Abstract】 Cu_xBi2Se3 is a superconductor that is a potential candidate for topological supercoDducton We report our laserbased angle-resolved photoemission measurement on the electronic structure of the Cu_xBi2Se3 superconductor, and a detailed magneto-resistance measurement in both normal and superconducting states. We iiiid that the topological surface state of the pristine Bi2Se3 topological insulator remains robust after the Cu-intercalation,while the Dirac cone location moves downward due to electron doping. Detailed measurement on the magnetic field-dependence of the resistance in the superconducting state establishes an irreversibility line and gives a value of the upper critical field at zero temperature of ⁴000 Oe for the Cu_xBi2Se3 superconductor with a middle point Tc of 1.9 K. The relation between the upper critical Geld H_C2 and temperature T is dilFerent from the usual scaling relation found in cuprates and in other kinds of superconductors. Small positive magneto-resistance is observed in Cu_xBi2Se3 superconductors up to room temperature. These observations provide useful information for further study of this possible candidate for topological superconductors.更多还原