1206.2985 (T. Sudayama et al.)

Doping-Dependent and Orbital-Dependent Band Renormalization in
Ba(Fe_1-xCo_x)_2As_2 Superconductors    [PDF]

T. Sudayama, Y. Wakisaka, T. Mizokawa, S. Ibuka, R. Morinaga, T. J. Sato, M. Arita, H. Namatame, M. Taniguchi, N. L. Saini

Angle resolved photoemission spectroscopy of Ba(Fe1-xCox)2As2 (x = 0.06, 0.14, and 0.24) shows that the width of the Fe 3d yz/zx hole band depends on the doping level. In contrast, the Fe 3d x^2-y^2 and 3z^2-r^2 bands are rigid and shifted by the Co doping. The Fe 3d yz/zx hole band is flattened at the optimal doping level x = 0.06, indicating that the band renormalization of the Fe 3d yz/zx band correlates with the enhancement of the superconducting transition temperature. The orbital-dependent and doping-dependent band renormalization indicates that the fluctuations responsible for the superconductivity is deeply related to the Fe 3d orbital degeneracy.

View original: http://arxiv.org/abs/1206.2985