Electronic Structure, Irreversibility Line and Magnetoresistance of Cu0.3Bi2Se3 Superconductor

• Published in: Chinese physics letters Vol. 32; no. 6; pp. 141 - 145
• Main Author: 伊合绵 陈朝宇 孙璇 谢卓晋 冯娅 梁爱基 彭莹莹 何少龙 赵林 刘国东 董晓莉 张君 陈创天 许祖彦 顾根大 周兴江
• Format: Journal Article
• Language: English
• Published: United States IOP Publishing 01.06.2015
• Subjects: CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Dirac; 不可逆线; 临界磁场; 电子结构; 电子能谱测量; 磁电阻; 超导体; 铜氧化物
• ISSN: 0256-307X; 1741-3540
• DOI: 10.1088/0256-307X/32/6/067401

Cux Bi2Se3 is a superconductor that is a potential candidate for topological superconductors. We report our laser- based angle-resolved photoemission measurement on the electronic structure of the CuxBi2Se3 superconductor, and a detailed magneto-resistance measurement in both normal and superconducting states. We find that the topological surface state of the pristine Bi2Se3 topological insulator remains robust after the Cu-intercalation, while the Dirae cone location moves downward due to electron doping. Detailed measurements 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 Cu0.3Bi2Se3 superconductor with a middle point Tc of 1.g K. The relation between the upper critical field He2 and temperature T is different from the usual scaling relation found in cuprates and in other kinds of superconductors. Small positive magneto-resistance is observed in Cuo.3Bi2Se3 superconductors up to room temperature. These observations provide useful information for further study of this possible candidate for topological superconductors.