Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dipolar interaction and incoherent quantum tunneling: a Monte Carlo
  study of magnetic relaxation   We study the magnetic relaxation of a system of localized spins interacting
through weak dipole interactions, at a temperature large with respect to the
ordering temperature but low with respect to the crystal field level splitting.
The relaxation results from quantum spin tunneling but is only allowed on sites
where the dipole field is very small. At low times, the magnetization decrease
is proportional to $\sqrt{t}$ as predicted by Prokofiev and Stamp, and at long
times the relaxation can be described as an extension of a relaxed zone. The
results can be directly compared with very recent experimental data on Fe_8
molecular clusters.

29
The categories of this paper are: funct-an
17
The categories of this paper are: q-fin
9
The categories of this paper are: nlin
31
The categories of this paper are: ao-sci
8
The categories of this paper are: hep-ex
34
The categories of this paper are: chem-ph
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
26
The categories of this paper are: bayes-an
19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph
2
The categories of this paper are: math
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat