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Charge density waves in Sr_14-xCa_xCu_24O_41: electron correlations vs. structural effects

K. -Y. Choi·M. Grove·P. Lemmens·M. Fischer·G. Güntherodt·U. Ammerahl·B. Büchner·G. Dhalenne·A. Revcolevschi·J. Akimitsu
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Abstract

We report inelastic light scattering experiments in the spin-chain and ladder system Sr_14-xCa_xCu_24O_41. A depletion of an electronic background is observed for 0 < x < 5 at low temperatures and with light polarization both parallel to the leg and rung directions. This points to the formation of 2D charge density wave in the ladders. Furthermore, the Ca-substitution dependence of the 305- and 249-cm-1 modes, sensitive to the lattice modulations of the respective chain and ladder system, suggests that the charge dynamics in the ladders is strongly influenced by the structural incommensurability.

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K. -Y. Choi, M. Grove, P. Lemmens, M. Fischer, G. Güntherodt, U. Ammerahl, B. Büchner, G. Dhalenne, A. Revcolevschi, J. Akimitsu. 2006-01-10. Charge density waves in Sr_14-xCa_xCu_24O_41: electron correlations vs. structural effects. https://doi.org/10.1103/physrevb.73.104428

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