摘要
We use scanning tunneling microscopy to study the temperature evolution of electronic structure in Ca_(3)Cu_(2)O_(4)Cl_(2) parent Mott insulator of cuprates. It is found that the upper Hubbard band moves towards the Fermi energy with increasing temperature, while the charge transfer band remains basically unchanged. This leads to a reduction of the charge transfer gap size at high temperatures, and the rate of reduction is much faster than that of conventional semiconductors. Across the Neel temperature for antiferromagnetic order, there is no sudden change in the electronic structure. These results shed new light on the theoretical models about the parent Mott insulator of cuprates.
作者
Haiwei Li
Shusen Ye
Jianfa Zhao
Changqing Jin
Yayu Wang
李海威;叶树森;赵建发;靳常青;王亚愚(State Key Laboratory of Low-Dimensional Quantum Physics,Department of Physics,Tsinghua University,Beijing 100084,China;Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;Songshan Lake Materials Laboratory,Dongguan 523808,China;School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Frontier Science Center for Quantum Information,Beijing 100084,China)
基金
supported by the National Key Research and Development Program of China (Grant No. 2017YFA0302900)
the Basic Science Center Project of the National Natural Science Foundation of China (Grant No. 51788104)
supported in part by the Beijing Advanced Innovation Center for Future Chip (ICFC)。
