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J. Chang[1], S. Pailhes[1], M. Shi[2], M. Mansson[3], T. Claesson[3], O. Tjernberg[3], A. Schnyder[1], C. Mudry[1] and
J. Mesot[1].
[1] ETH Zurich and Paul Scherrer Institut, Switzerland [2] Swiss Light Source, Paul Scherrer Institut, Switzerland [3] Royal Institut of Technology KTH, Sweden A fascinating aspect in strongly correlated materials is the coupling between various degrees of freedom (electronic, magnetic, lattice, Ä). In spectra obtained from Angle Resolved PhotoEmission Spectroscopy (ARPES), such a coupling manifests itself via complex momentum and energy dependences of the spectral function. Recently, ARPES experiments revealed the entire electronic structure up to 1.5eV [1,2,3,4,5,6]. It seems that the spectral function is mainly divided into two parts : 1) a low energy part with well defined quasiparticles and 2) a broad high-energy incoherent feature. The borderline between both components is characterized by the appearance of "giant" anomalies both in the dispersion and life-time. We provide the full momentum dependence of these anomalies in optimally doped La2-x SrxCuO4, and we found that the boundary between the low-energy and high-energy features exhibits a cosine-shaped momentum dependence. Theorectical implications of our observations will be discussed. [1] J. Chang et al., cond-mat/0610880 (2006). [2] J. Graf et al ., cond-mat/ 0607319 (2006). [3] B. P. Xie et al ., cond-mat/ 0607450 (2006). [4] T. Valla et al, cond-mat/0610249 (2006). [5] Z.-H. Pan et al, cond-mat/0610442 (2006). [6] W. Meevasana et al, cond-mat/0612541 (2006). |
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