Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Bond Randomness Induced Magnon Decoherence in a Spin-1/2 Ladder Compound   We have used a combination of neutron resonant spin-echo and triple-axis
spectroscopies to determine the energy and linewidth of the magnon resonance in
IPA-Cu(Cl$_{0.95}$Br$_{0.05}$)$_3$, a model spin-1/2 ladder antiferromagnet
where Br substitution induces bond randomness. We find that the bond defects
induce a blueshift, $\delta \Delta$, and broadening, $\delta \Gamma$, of the
magnon gap excitation compared to the pure compound. At temperatures exceeding
the energy scale of the inter-ladder exchange interactions, $\delta \Delta$ and
$\delta \Gamma$ are temperature independent within the experimental error, in
agreement with Matthiessen's rule according to which magnon-defect scattering
yields a temperature independent contribution to the magnon mean free path.
Upon cooling, $\delta \Delta$ and $\delta \Gamma$ become temperature dependent
and saturate at values lower than those observed at higher temperature,
consistent with the crossover from one-dimensional to two-dimensional spin
correlations with decreasing temperature previously observed in pure
IPA-CuCl$_3$. These results indicate limitations in the applicability of
Matthiessen's rule for magnon scattering in low-dimensional magnets.

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The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph
24
The categories of this paper are: dg-ga
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The categories of this paper are: nucl-th
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The categories of this paper are: cs
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
13
The categories of this paper are: quant-ph
37
The categories of this paper are: supr-con
2
The categories of this paper are: math
19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
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The categories of this paper are: q-fin
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The categories of this paper are: q-alg
25
The categories of this paper are: patt-sol