Regensburg 2004 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 8: Postersitzung I: Supraleitung

TT 8.42: Poster

Montag, 8. März 2004, 14:30–19:00, Poster A

Raman study of charge ordering instabilities in La_2−xSr_xCuO₄ — •Leonardo Tassini¹, Francesca Venturini¹, Rudi Hackl¹, Qing-ming Zhang², N. Kikugawa³, and Tojitsu Fujita³ — ¹Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, D-85748 Garching — ²Department of Physics, Nanjing University, Nanjing 210093, P.R. China — ³ADSM, Hiroshima University, Higashi-Hiroshima 739-8526, Japan

The electronic Raman effect has been studied in differently doped single crystals of La_2−xSr_xCuO₄ (LSCO). At low energies and temperatures new structures indicating a very high conductivity are found for which there is no evidence in Bi2212 and Y123. In the same temperature range a related low-energy mode is found in the optical conductivity. For the selection rules and for similarities with ladder compounds we conclude that the features are an indication of incipient charge ordering and 1D conduction. The correlation length of these stripes is at least of the order of the electronic mean free path in LSCO. The direction of the 1D structures is along the diagonals and the principle axes for x=0.02 and x=0.10, respectively.