Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Discovery of slow magnetic fluctuations and critical slowing down in the
  pseudogap phase of YBa$_2$Cu$_3$O$_y$   Evidence for intra-unit-cell (IUC) magnetic order in the pseudogap region of
high-$T_c$ cuprates below a temperature $T^\ast$ is found in several studies,
but NMR and $\mu$SR experiments do not observe the expected static local
magnetic fields. It has been noted, however, that such fields could be averaged
by fluctuations. Our measurements of muon spin relaxation rates in single
crystals of YBa$_2$Cu$_3$O$_y$ reveal magnetic fluctuations of the expected
order of magnitude that exhibit critical slowing down at $T^\ast$. These
results are strong evidence for fluctuating IUC magnetic order in the pseudogap
phase.

11
The categories of this paper are: hep-lat
21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
7
The categories of this paper are: hep-th
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
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The categories of this paper are: solv-int
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex