BCS-like Bogoliubov quasiparticles in high-T(c) superconductors observed by angle-resolved photoemission spectroscopy

Phys Rev Lett. 2003 May 30;90(21):217002. doi: 10.1103/PhysRevLett.90.217002. Epub 2003 May 29.

Abstract

We performed high-resolution angle-resolved photoemission spectroscopy on triple-layered high-T(c) cuprate Bi(2)Sr(2)Ca(2)Cu(3)O(10+delta). We have observed the full energy dispersion (electron and hole branches) of Bogoliubov quasiparticles and determined the coherence factors above and below E(F) as a function of momentum from the spectral intensity as well as from the energy dispersion based on BCS theory. The good quantitative agreement between the experiment and the theoretical prediction suggests the basic validity of BCS formalism in describing the superconducting state of cuprates.