Superconducting electronic state in optimally doped YBa2Cu3O7-d observed with laser-excited angle-resolved photoemission spectroscopy
| Autor: | Okawa, M., Ishizaka, K., Uchiyama, H., Tadatomo, H., Masui, T., Tajima, S., Wang, X. -Y., Chen, C. -T., Watanabe, S., Chainani, A., Saitoh, T., Shin, S. |
|---|---|
| Rok vydání: | 2008 |
| Předmět: | |
| Zdroj: | Phys. Rev. B 79, 144528 (2009) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevB.79.144528 |
| Popis: | Low energy electronic structure of optimally doped YBa2Cu3O7-d is investigated using laser-excited angle-resolved photoemission spectroscopy. The surface state and the CuO chain band that usually overlap the CuO2 plane derived bands are not detected, thus enabling a clear observation of the bulk superconducting state. The observed bilayer splitting of the Fermi surface is ~0.08 angstrom^{-1} along the (0,0)-(pi,pi) direction, significantly larger than Bi2Sr2CaCu2O8+d. The kink structure of the band dispersion reflecting the renormalization effect at ~60 meV shows up similarly as in other hole-doped cuprates. The momentum-dependence of the superconducting gap shows d_{x^2-y^2}-wave like amplitude, but exhibits a nonzero minimum of ~12 meV along the (0,0)-(pi,pi) direction. Possible origins of such an unexpected "nodeless" gap behavior are discussed. Comment: 9 pages, 10 figures; revised version accepted for publication in Phys. Rev. B |
| Databáze: | arXiv |
| Externí odkaz: |
|