Dresden 2006 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 30: Superconductivity: Twenty Years High-Tc Cuprates - Recent Progress
TT 30.1: Vortrag
Donnerstag, 30. März 2006, 14:00–14:15, HSZ 02
Electron-phonon coupling reflecting dynamic charge inhomogeneity in copper-oxide superconductors — •Dmitri Reznik1, L. Pintschovious1, M Ito2, S. Iikubo2, M. Sato2, H. Goka3, M. Fujita3, K. Yamada3, G. Gu4, and J.M. Tranquada4 — 1Forschungszentrum Karlsruhe, Institut für Festkörperphysik, P.O.B. 3640, D-76021 Karlsruhe, Germany — 2Department of Physics, Division of Materials Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan — 3Institute for Material Research, Tohoku University, Katahira, Aoba-ku, Sendai, 980-8577, Japan — 4Physics Department, Brookhaven National Laboratory, Upton, New York 11973
The attempt to understand cuprate superconductors is complicated by the presence of multiple strong interactions. While many believe that antiferromagnetism is important for the superconductivity, there has been resurgent interest in electron-lattice coupling. The conventional superconductor MgB2 has a very strong electron-lattice coupling predicted by standard theory. We show that there is a similarly strong anomaly in the Cu-O bond-stretching phonon in cuprate superconductors however, this behavior is completely absent in conventional calculations. Instead, the anomaly is strongest in compounds that exhibit static stripe order.It occurs at a wave vector corresponding to the charge order. The results suggest that this giant electron-phonon anomaly, which is absent in undoped and over-doped non-superconductors, is associated with charge inhomogeneity. It follows that electron-phonon coupling may be important to understanding superconductivity although its contribution to the mechanism is likely indirect.