## Comparison of charge modulations in La$_{1.875}$Ba$_{0.125}$CuO$_4$ and YBa$_2$Cu$_3$O$_{6.6}$    [PDF]

V. Thampy, S. Blanco-Canosa, M. García-Fernández, M. P. M. Dean, G. D. Gu, M. Föerst, B. Keimer, M. Le Tacon, S. B. Wilkins, J. P. Hill
A charge modulation has recently been reported in (Y,Nd)Ba$_2$Cu$_3$O$_{6+x}$ [Ghiringhelli {\em et al.} Science 337, 821 (2013)]. Here we report Cu $L_3$ edge soft x-ray scattering studies comparing the lattice modulation associated with the charge modulation in YBa$_2$Cu$_3$O$_{6.6}$ with that associated with the well known charge and spin stripe order in La$_{1.875}$Ba$_{0.125}$CuO$_4$. We find that the correlation length in the CuO$_2$ plane is isotropic in both cases, and is $259 \pm 9$ \AA for La$_{1.875}$Ba$_{0.125}$CuO$_4$ and $55 \pm 15$ \AA for YBa$_2$Cu$_3$O$_{6.6}$. Assuming weak inter-planar correlations of the charge ordering in both compounds, we conclude that the order parameters of the lattice modulations in La$_{1.875}$Ba$_{0.125}$CuO$_4$ and YBa$_2$Cu$_3$O$_{6.6}$ are of the same order of magnitude.
View original: http://arxiv.org/abs/1305.5515