Berlin 2008 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 33: Symposium: High-Temperature Superconductivity

TT 33.9: Talk

Thursday, February 28, 2008, 17:05–17:30, H 0104

Charge ordering phenomena and superconductivity in cuprates — •Leonardo Tassini, Bernhard Muschler, Wolfgang Prestel, Rudi Hackl, Michael Lambacher, and Andreas Erb — Walther-Meissner-Institut, 85748 Garching, Germany

The relationship between charge ordering phenomena and superconductivity was investigated with electronic Raman scattering in La_2−xSr_xCuO₄ (LSCO) and Y_1−yCa_yBa₂Cu₃O_6+x (Y-123) single crystals. New low-energy excitations were found that are interpreted in terms of dynamical stripes. Below the onset point of superconductivity p_sc1 the stripes are oriented along the diagonal of the CuO₂ planes for both LSCO and Y-123. The Raman data indicate that diagonal stripes compete with superconductivity. Apparently, stripes along the Cu−O direction lead to a relatively low-T_c such as in LSCO, while two-dimensional ordering such as observed by neutron scattering in Y-123 leads to high-T_c of the order of 100 K.

The project has been supported by the DFG under grant number Ha2071/3-1 via the Research Unit FOR 538.