2003/01/03 by F. Ronning, T. Sasagawa, Y. Kohsaka +13 · 1 citation
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Copper-based nanomaterials and applications #Physics of Superconductivity and Magnetism #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.67.165101
10 pages, 12 figures, accepted by PRB; a high quality pdf is available at http://helios.physics.utoronto.ca/~fronning/RonningNaCCOCResub.pdf (2.2MB)
arxiv created 2003/01/03 · openalex publication_date 2003/04/02 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We present angle resolved photoemission data on Na-doped Ca2CuO2Cl2. We demonstrate that the chemical potential shifts upon doping the system across the insulator to metal transition. The resulting low-energy spectra reveal a gap structure which appears to deviate from the canonical d_x2\ensuremath-y2\ensuremath∝|cos(kxa)\ensuremath-cos(kya)| form. To reconcile the measured gap structure with d-wave superconductivity one can understand the data in terms of two gaps, a very small one contributing to the nodal region and a very large one dominating the antinodal region. The latter is a result of the electronic structure observed in the undoped antiferromagnetic insulator. Furthermore, the low-energy electronic structure of the metallic sample contains a two component structure in the nodal direction, and a change in velocity of the dispersion in the nodal direction at roughly 50 meV. We discuss these results in connection with photoemission data on other cuprate systems.