Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spin Stiffness of Mesoscopic Quantum Antiferromagnets   We study the spin stiffness of a one-dimensional quantum antiferromagnet in
the whole range of system sizes $L$ and temperatures $T$. We show that for
integer and half-odd integer spin case the stiffness differs fundamentally in
its $L$ and $T$ dependence, and that in the latter case the stiffness exhibits
a striking dependence on the parity of the number of sites. Integer spin chains
are treated in terms of the non-linear sigma model, while half-odd integer spin
chains are discussed in a renormalization group approach leading to a Luttinger
liquid with Aharonov-Bohm type boundary conditions.

17
The categories of this paper are: q-fin
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg
24
The categories of this paper are: dg-ga
2
The categories of this paper are: math
11
The categories of this paper are: hep-lat
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
13
The categories of this paper are: quant-ph
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom