Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Revisiting and modeling the magnetism of hole-doped CuO_2 spin chains in
  Sr{14-x}Ca_xCu_{24}O_{41}   Magnetization measurements of Sr{14-x}Ca_xCu_{24}O_{41} with 0 <= x <=12 in
magnetic fields up to 16 T show that the low-temperature magnetic response of
the CuO_2 spin chains changes strongly upon Ca doping. For x=0 quantum
statistical simulations yield that the temperature and field dependence of the
magnetization can be well described by an effective Heisenberg model in which
the ground state configuration is composed of spin dimers, trimers, and
monomers. For x>0 a constant contribution to the low-temperature magnetic
susceptibility is observed which cannot be explained in terms of simple chain
models. Alternative scenarios are outlined.

16
The categories of this paper are: stat
13
The categories of this paper are: quant-ph
12
The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
5
The categories of this paper are: gr-qc
14
The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph