Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Semi-Classical Analysis of Order from Disorder   We study in this paper the Heisenberg antiferromagnet with nearest neighbours
interactions on the Husimi cactus, a system which has locally the same topology
as the Kagom\'e lattice. This system has a huge classical degeneracy
corresponding to an extensive number of degrees of freedom.We show that unlike
thermal fluctuations, quantum fluctuations lift partially this degeneracy and
favour a discrete subset of classical ground states. In order to clarify the
origin of these effects, we have set up a general semi-classical analysis of
the order from disorder phenomenon and clearly identified the differences
between classical and quantum fluctuations. This semi-classical approach also
enables us to classify various situations where a selection mechanism still
occurs. Moreover, once a discrete set of ground states has been preselected,
our analysis suggests that tunelling processes within this set should be the
dominant effect underlying the strange low energy spectrum of Kagom\'e-like
lattices.

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The categories of this paper are: q-bio
17
The categories of this paper are: q-fin
35
The categories of this paper are: mtrl-th
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The categories of this paper are: math-ph
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The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
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The categories of this paper are: alg-geom
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The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg
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The categories of this paper are: hep-ex
2
The categories of this paper are: math
24
The categories of this paper are: dg-ga
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The categories of this paper are: econ
26
The categories of this paper are: bayes-an
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The categories of this paper are: nlin