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Suppression of the charge-density-wave state in Sr_14Cu_24O_41 by calcium doping

T. Vuletic·B. Korin-Hamzic·S. Tomic·B. Gorshunov·P. Haas·T. Room·M. Dressel·J. Akimitsu·T. Sasaki·T. Nagata
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Abstract

The charge response in the spin chain/ladder compound Sr_14-xCa_xCu_24O_41 is characterized by DC resistivity, low-frequency dielectric spectroscopy and optical spectroscopy. We identify a phase transition below which a charge-density wave (CDW) develops in the ladder arrays. Calcium doping suppresses this phase with the transition temperature decreasing from 210 K for x=0 to 10 K for x=9, and the CDW gap from 130 meV down to 3 meV, respectively. This suppression is due to the worsened nesting originating from the increase of the inter-ladder tight-binding hopping integrals, as well as from disorder introduced at the Sr sites. These results altogether speak in favor of two-dimensional superconductivity under pressure.

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T. Vuletic, B. Korin-Hamzic, S. Tomic, B. Gorshunov, P. Haas, T. Room, M. Dressel, J. Akimitsu, T. Sasaki, T. Nagata. 2003-05-20. Suppression of the charge-density-wave state in Sr_14Cu_24O_41 by calcium doping. https://doi.org/10.1103/physrevlett.90.257002

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