|
Elementary excitations in the high-Tc cuprates are of central interest in order to learn more about the correlations and the pairing mechanism for superconductivity. In this talk I will discuss some recent experimental and theoretical work on the kink feature and resonance peak and their possible interpretations due to phonons and spin fluctuations [1-4]. It turns out that the kink seen in photoemission spectroscopy and the resonance peak observed in inelastic neutron scattering experiments are two key experiments revealing fingerprints of the paring interaction. Using an electronic theory, both experiments can be explained by assuming spin fluctuations as the relevant mechanism for Cooper-pairing [5]. In a next step, the doping dependence of the elementary excitations will be analyzed. Although the phase diagram of hole- and electron-doped cuprates reveal some similarities [6,7], both effects are only present in hole-doped cuprates, but not in electron-doped ones. The kink feature and resonance peak are also related to tunneling experiments
and measurements of the optical conductivity and shed important light on the essential ingredients a theory for Cooper-pairing in the cuprates must contain [5].
[1] see, for example, A. Lanzara et al., Nature 412, 510 ('01) [2] H.F. Fong et al., PRB 54, 6708; Ph. Bourges et al., Science 288, 1234 ('00) [3] D. Manske, I. Eremin, and K.H. Bennemann, PRB 63, 054517('01) [4] D. Manske, I. Eremin, and K.H. Bennemann, PRL 87, 177005('01) [5] D. Manske, I. Eremin, and K.H. Bennemann, PRB 67, 134520('03) [6] D. Manske, T. Dahm, and K.H. Bennemann, PRB 64, 144520 ('01) [7] D. Manske, I. Eremin, and K.H. Bennemann, PRB 63, 13922 ('00) |