Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Comparison of charge modulations in La$_{1.875}$Ba$_{0.125}$CuO$_4$ and
  YBa$_2$Cu$_3$O$_{6.6}$   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.

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The categories of this paper are: nucl-ex
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The categories of this paper are: eess
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The categories of this paper are: patt-sol
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The categories of this paper are: ao-sci
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The categories of this paper are: hep-lat
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-ph
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The categories of this paper are: math
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The categories of this paper are: supr-con
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The categories of this paper are: econ
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The categories of this paper are: comp-gas
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The categories of this paper are: alg-geom
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The categories of this paper are: solv-int
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The categories of this paper are: adap-org
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The categories of this paper are: acc-phys
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The categories of this paper are: plasm-ph