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Etude par spectroscopie infrarouge de l'électrodynamique du supraconducteur Pr2-xCexCuO4 et de la manganite La2/3 Ca1/3 Mn03

Abstract : We report the temperature dependence of the infrared-visible ab plane response of Pr2-xCexCuO4. In the normal state, when varying the doping from a non-superconducting film x=0.11 to a superconducting overdoped film x=0.17, we observe a partial gap opening up to optimal doping x=0.15. A spin density wave gap model reproduces qualitatively our data. The magnitude of this gap extrapolates to zero for x=0.17 indicating the existence of a quantum critical point at this Ce concentration and the coexistence of magnetism and superconductivity. Below Tc for x=0.15 and x=0.17, the modification of the optical spectra at energies less than 2Delta=4.7kBTc is interpreted as the opening of the superconducting gap. The measured optical response of La2/3Ca1/3MnO3 is analyzed with an effective medium approximation model. An extra absorption close to the insolating/metallic transition temperature is interpreted as the signature of percolation in the sample.
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https://tel.archives-ouvertes.fr/tel-00007797
Contributor : Alexandre Zimmers <>
Submitted on : Thursday, December 16, 2004 - 8:21:34 PM
Last modification on : Monday, December 14, 2020 - 9:55:40 AM
Long-term archiving on: : Thursday, September 13, 2012 - 1:50:25 PM

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  • HAL Id : tel-00007797, version 1

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Alexandre Zimmers. Etude par spectroscopie infrarouge de l'électrodynamique du supraconducteur Pr2-xCexCuO4 et de la manganite La2/3 Ca1/3 Mn03. Supraconductivité [cond-mat.supr-con]. Université Pierre et Marie Curie - Paris VI, 2004. Français. ⟨tel-00007797⟩

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