Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Magnetic and Charge Fluctuations in High-$T_c$ Superconductors   Neutron scattering has been used to study the spin fluctuations in the
YBa$_2$Cu$_3$O$_{7-x}$ and Bi$_2$Sr$_2$CaCu$_2$O$_8$ materials. Evidence is
found for both incommensurate fluctuations and a commensurate resonance
excitation. Measurements on the lattice dynamics for YBa$_2$Cu$_3$O$_{6.6}$
show incommensurate structure that appears to stem from charge fluctuations
that are associated with the spin fluctuations.

35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
0
The categories of this paper are: hep-ph
36
The categories of this paper are: cmp-lg
32
The categories of this paper are: atom-ph
28
The categories of this paper are: alg-geom
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
6
The categories of this paper are: astro-ph
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con