By performing angle-resolved photoemission spectroscopy of the bilayer colossal magnetoresistive (CMR) manganite, La2−2xSr1+2xMn2O7, we provide the complete mapping of the Fermi level spectral weight topology. Clear and unambiguous bilayer splitting of the in-plane 3dx2−y2 band, mapped throughout the Brillouin zone, and the full mapping of the 3d3z2−r2 band are reported. Peculiar doping and temperature dependencies of these bands imply that as transition from the ferromagnetic metallic phase approaches, either as a function of doping or temperature, coherence along the c-axis between planes within the bilayer is lost, resulting in reduced interplane coupling. These results suggest that interplane coupling plays a large role in the CMR transition.
@article{arxiv.0806.2120,
title = {Bilayer splitting and c-axis coupling in bilayer manganites showing colossal magnetoresistance},
author = {C. Jozwiak and J. Graf and S. Y. Zhou and A. Bostwick and Eli Rotenberg and H. Zheng and J. F. Mitchell and A. Lanzara},
journal= {arXiv preprint arXiv:0806.2120},
year = {2009}
}