Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: More Evidence for a Distribution of Tunnel Splittings in
  Mn$_{12}$-acetate   In magnetic fields applied parallel to the anisotropy axis, the magnetization
of Mn$_{12}$ has been measured in response to a field that is swept back and
forth across the resonances corresponding to steps $N=4,5,...9$. The fraction
of molecules remaining in the metastable well after each sweep through the
resonance is inconsistent with expectations for an ensemble of identical
molecules. The data are consistent instead with the presence of a broad
distribution of tunnel splittings. A very good fit is obtained for a Gaussian
distribution of the second-order anisotropy tunneling parameter $X_E=-\ln(\mid
E\mid/2D)$. We show that dipolar shuffling is a negligible effect which cannot
explain our data.

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The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
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The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
18
The categories of this paper are: econ
11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
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The categories of this paper are: q-fin
5
The categories of this paper are: gr-qc
8
The categories of this paper are: hep-ex
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The categories of this paper are: eess
31
The categories of this paper are: ao-sci
34
The categories of this paper are: chem-ph
26
The categories of this paper are: bayes-an