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arXiv · 1904.08258

Phonon anomalies with doping in superconducting oxychlorides Ca2-xCuO2Cl2

Blair W. Lebert·Hajime Yamamoto·Masaki Azuma·Rolf Heid·Satoshi Tsutsui·Hiroshi Uchiyama·Alfred Q. R. Baron·Benoît Baptiste·Matteo d'Astuto
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Abstract

We measure the dispersion of the Cu-O bond-stretching phonon mode in the high-temperature superconducting parent compound Ca$_2$CuO$_2$Cl$_2$. Our density functional theory calculations predict a cosine-shaped bending of the dispersion along both the ($ξ$00) and ($ξξ$0) directions, while comparison with previous results on Ca$_{1.84}$CuO$_2$Cl$_2$ show it only along ($ξ$00), suggesting an anisotropic effect which is not reproduced in calculation at optimal doping. Comparison with isostructural La$_{2-x}$Sr$_x$CuO$_4$ suggests that these calculations reproduce well the overdoped regime, however they overestimate the doping effect on the Cu-O bond-stretching mode at optimal doping.

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Blair W. Lebert, Hajime Yamamoto, Masaki Azuma, Rolf Heid, Satoshi Tsutsui, Hiroshi Uchiyama, Alfred Q. R. Baron, Benoît Baptiste, Matteo d'Astuto. 2019-04-17. Phonon anomalies with doping in superconducting oxychlorides Ca2-xCuO2Cl2. https://doi.org/10.1103/physrevb.101.020506

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