Evidence of Electron Coupling to High Energy Excitations in a High Temperature Superconductor

ORAL

Abstract

We have carried out super-high resolution angle-resolved photoemission measurements on temperature evolution of the electron dynamics along the (0,0)-($\pi$,$\pi$) nodal direction in an optimally-doped Bi$_2$Sr$_2$CaCu$_2$O$_8$ high temperature superconductor. The nodal photoemission spectra exhibit dramatic sharpening with decreasing temperature, with an obvious change in the scattering rate across T$_c$. New high energy features are found to develop at $\sim$115meV and $\sim$150meV, besides the prominent $\sim$70 meV one, in the nodal electron self-energy in the superconducting state. These observations provide evidence that, in addition to coupling with low energy excitations like phonons or magnetic resonance mode, there are high-energy excitations involved in the electron coupling.

–

Authors

  • Xingjiang Zhou

  • Wentao Zhang

  • Guodong Liu

  • Lin Zhao

  • Haiyun Liu

  • Jianqiao Meng

  • Xiaoli Dong

  • Wei Lu

  • Zhongxian Zhao

  • Guiling Wang

  • Hongbo Zhang

  • Yong Zhou

  • Zuyan Xu

    • Institute of Physics, Chinese Academy of Sciences, Beijing 100080

  • Yong Zhu

  • Xiaoyang Wang

  • Chuangtian Chen

    • Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100080

  • J.S. Wen

  • Z.J. Xu

  • Genda Gu

    • Brookhaven National Laboratory, Upton, New York 11973

  • T. Sasagawa

    • Tokyo Institute of Technology, Yokohama Kanagawa, Japan