Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Anisotropic charge transfer mechanism in La$_{2-x}$Sr$_x$CuO$_4$ and
  Bi$_2$Sr$_2$Ca$_{1-x}$Y$_x$Cu$_2$O$_{8+\delta}$   Raman spectra of La$_{2-x}$Sr$_x$CuO$_4$ are similar to those of
Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ except for the split two-magnon peaks at the
stripe phase and the stronger step-like decrease in the low energy $B_{\rm 2g}$
spectra. The suppressed $B_{\rm 1g}$ spectral region below the two-magnon peak
decreases as the carrier density increases, whereas the energy of the step-like
suppression is little dependent on the carrier density. It suggests the
anisotropic charge transfer mechanism coupled with magnetic excitations along
the nearest neighbor Cu sites and the phononic excitations along the diagonal
direction.

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The categories of this paper are: math
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
13
The categories of this paper are: quant-ph
16
The categories of this paper are: stat
21
The categories of this paper are: adap-org
24
The categories of this paper are: dg-ga
12
The categories of this paper are: nucl-th