Temperature Evolution of Energy Gap and Band Structure in the Superconducting and Pseudogap States of Bi_(2)Sr_(2)CaCu_(2)O_(8+δ)Superconductor Revealed by Laser-Based Angle-Resolved Photoemission Spectroscopy  

作　　者：Xuan Sun Wen-Tao Zhang Lin Zhao Guo-Dong Liu Gen-Da Gu Qin-Jun Peng Zhi-Min Wang Shen-Jin Zhang Feng Yang Chuang-Tian Chen Zu-Yan Xu Xing-Jiang Zhou 孙璇;张文涛;赵林;刘国东;顾根大;彭钦军;王志敏;张申金;杨峰;陈创天;许祖彦;周兴江(National Laboratory for Superconductivity,Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190;University of Chinese Academy of Sciences,Bering 100049;Condensed Matter Physics and Materials Science Department,Brookhaven National Laboratory,Upton,New York 11973,USA;Technical Institute of Physics and Chemistry,Chinese Academy of Sciences,Beijing 100190;Collaborative Innovation Center of Quantum Matter,Beijing 100871)

机构地区：[1]National Laboratory for Superconductivity,Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190 [2]University of Chinese Academy of Sciences,Bering 100049 [3]Condensed Matter Physics and Materials Science Department,Brookhaven National Laboratory,Upton,New York 11973,USA [4]Technical Institute of Physics and Chemistry,Chinese Academy of Sciences,Beijing 100190 [5]Collaborative Innovation Center of Quantum Matter,Beijing 100871

出　　处：《Chinese Physics Letters》2018年第1期90-94,共5页中国物理快报(英文版)

基　　金：Supported by the National Key Research and Development Program of China under Grant No 2016YFA0300300;the National Natural Science Foundation of China under Grant No 11334010;the National Basic Research Program of China under Grant No2015CB921300;the Strategic Priority Research Program(B)of the Chinese Academy of Sciences under Grant No XDB07020300

摘　　要：We carry out detailed momentum-dependent and temperature-dependent measurements on Bi_(2)Sr_(2)CaCu_(2)O_(8+δ)(Bi2212)superconductor in the superconducting and pseudogap states by super-high resolution laser-based angleresolved photoemission spectroscopy.The precise determination of the superconducting gap for the nearly optimally doped Bi2212(T_(c)=91 K)at low temperature indicates that the momentum-dependence of the superconducting gap deviates from the standard d-wave form(cos(2Φ)).It can be alternatively fitted by including a high-order term(cos(6Φ))in which the next nearest-neighbor interaction is considered.We find that the band structure near the antinodal region smoothly evolves across the pseudogap temperature without a signature of band reorganization which is distinct from that found in Bi_(2)Sr_(2)CuO_(6+δ)superconductors.This indicates that the band reorganization across the pseudogap temperature is not a universal behavior in cuprate superconductors.These results provide new insights in understanding the nature of the superconducting gap and pseudogap in high-temperature cuprate superconductors.

分 类 号：O511.3[一般工业技术—材料科学与工程]