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arXiv · 0708.1027

Unusual oxygen isotope effects in cuprates -- importance of doping

G. -H. Gweon·T. Sasagawa·H. Takagi·D. -H. Lee·A. Lanzara
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Abstract

A recent angle resolved photoelectron spectroscopy (ARPES) study by Douglas et al. \cite {dessau-comment} on oxygen isotope exchanged Bi_2Sr_2CaCu_2O$_{8+δ}$ superconductors reported an absence of isotope effect at optimal doping, questioning the previous work by us \cite {gweon-nature}. Here, we report a new result that sheds light on this puzzling discrepancy as well as the nature of the electron lattice interaction in the cuprates: the anomalous isotope effect at optimal doping \cite {gweon-nature}, re-confirmed here, vanishes on a mere 2 % overdoping of holes. This result implies a rapid change of the nature of the electron-lattice interaction near optimal doping. We also find that the data by Douglas et al. \cite {dessau-comment} are actually characteristic of significantly over-doped samples, not of optimally doped samples as they claimed.

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G. -H. Gweon, T. Sasagawa, H. Takagi, D. -H. Lee, A. Lanzara. 2007-08-07. Unusual oxygen isotope effects in cuprates -- importance of doping. https://arxiv.org/abs/0708.1027

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