Evolution from the Parent Mott Insulator to a Superconductor in Lightly Hole-Doped Bi2Sr2CaCu2O8+δ  

作　　者：Qiang Gao Lin Zhao Cheng Hu Hongtao Yan Hao Chen Yongqing Cai Cong Li Ping Ai Jing Liu Jianwei Huang Hongtao Rong Chunyao Song Chaohui Yin Qingyan Wang Yuan Huang Guo-Dong Liu Zu-Yan Xu Xing-Jiang Zhou 高强;赵林;胡成;闫宏涛;陈浩;蔡永青;李聪;艾平;刘静;黄建伟;戎洪涛;宋春尧;殷超辉;王庆艳;黄元;刘国东;许祖彦;周兴江(National Lab for Superconductivity,Beijing National laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Beijing Academy of Quantum Information Sciences,Beijing 100193,China;Songshan Lake Materials Laboratory,Dongguan 523808,China;Technical Institute of Physics and Chemistry,Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]National Lab for Superconductivity,Beijing National laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China [2]School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China [3]Beijing Academy of Quantum Information Sciences,Beijing 100193,China [4]Songshan Lake Materials Laboratory,Dongguan 523808,China [5]Technical Institute of Physics and Chemistry,Chinese Academy of Sciences,Beijing 100190,China

出　　处：《Chinese Physics Letters》2020年第8期123-129,共7页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China(Grant Nos.11888101,11922414,and 11534007);the National Key Research and Development Program of China(Grant Nos.2016YFA0300300 and 2017YFA0302900);the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(Grant No.XDB25000000);the Youth Innovation Promotion Association of CAS(Grant No.2017013);the Research Program of Beijing Academy of Quantum Information Sciences(Grant No.Y18G06).

摘　　要：High temperature superconductivity in cuprates is realized by doping the Mott insulator with charge carriers.A central issue is how such an insulating state can evolve into a conducting or superconducting state when charge carriers are introduced.Here,by in situ vacuum annealing and Rb deposition on the Bi2Sr2Ca0.6Dy0.4Cu2O8+δ(Bi2212)sample surface to push its doping level continuously from deeply underdoped(Tc=25K,doping level p^0.066)to the near-zero doping parent Mott insulator,angle-resolved photoemission spectroscopy measurements are carried out to observe the detailed electronic structure evolution in the lightly hole-doped region for the first time.Our results indicate that the chemical potential lies at about l eV above the charge transfer band for the parent state at zero doping,which is quite close to the upper Hubbard band.With increasing hole doping,the chemical potential moves continuously towards the charge transfer band and the band structure evolution exhibits a rigid band shift-like behavior.When the chemical potential approaches the charge transfer band at a doping level of^0.05,the nodal spectral weight near the Fermi level increases,followed by the emergence of the coherent quasiparticle peak and the insulator-superconductor transition.Our observations provide key insights in understanding the insulator-superconductor transition in doping the parent cuprate compound and for establishing related theories.

关 键 词：transition. DOPING SUPERCONDUCTOR 

分 类 号：O614.532[理学—无机化学] O511.3[理学—化学]