Recent scanning tunnelling microscopy (STM) studies on Bi2Sr2CaCu2O8+δ (Bi-2212) revealed the presence of severe inhomogeneity with length scale L0≈ξ0, the coherence length. Other studies have been interpreted in terms of mesoscale or nanoscale phase segregation. Here we analyze heat capacity and NMR data on Bi-2212 and (Y,Ca)Ba2Cu3O7−δ and find no evidence for phase segregation or gross inhomogeneity. For Bi-2212 the coherence scale L0 increases with doping from 5 to 17ξ0 and the hole density inhomogeneity decreases from 0.028 to 0.005 holes/Cu. We conclude that STM measurements considerably overstate the inhomogeneity in bulk Bi-2212.
@article{arxiv.cond-mat/0212461,
title = {Absence of gross inhomogeneity in HTS cuprates},
author = {J. W. Loram and J. L. Tallon and W. Y. Liang},
journal= {arXiv preprint arXiv:cond-mat/0212461},
year = {2013}
}
Comments
4 pages, 5 figures, submitted to Phys. Rev. Letters