Berlin 2008 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 15: Superconductivity: Poster Session
TT 15.15: Poster
Dienstag, 26. Februar 2008, 14:00–18:00, Poster B
The nature of the sharp peak — •Beate Müller, Lenart Dudy, Helmut Dwelk, Alica Krapf, Christoph Janowitz, and Recardo Manzke — Humboldt-Universität zu Berlin, Institut für Physik, Newtonstr. 15, 12489 Berlin
In the high-Tc cuprates the excitations investigated by photoemission in the antinodal direction are incoherent. Only at low temperatures a quasiparticle like excitation, the so-called sharp or superconducting peak, emerges. Mainly the sharp peak is interpreted as a coherent excitation marking e.g. a dimensional crossover [1] but it was also seen as the signature of superfluid density [2,3] or the consequence of the coupling to the magnetic resonance mode [4]. The distinction between the different approaches is the definition of the sharp peak as a consequence of a change in lineshape of the band theory derived excitations or as an additional excitation. In our opinion ARPES measurements at different photon energies point towards the sharp peak being an additional excitation. From this point of view it is possible to reevaluate the various models.
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[2] R. H. He, D. L. Feng, H. Eisaki, J.-I. Shimoyama, K. Kishio, and G. D. Gu, Phys. Rev. B 69, 220502 (2004)
[3] D. Feng, D. Lu, K. Shen, C. Kim, H. Eisaki, A. Damascelli, R. Yoshizaki, J.-i. Shimoyama, K. Kishio, G. Gu, Science 289, 277 (2000)
[4] M. Eschrig and M. R. Norman, Phys. Rev. Lett. 89, 277005 (2002)