Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ultrafast destruction and recovery of the spin density wave order in
  iron based pnictides: a multi-pulse optical study   We report on systematic excitation-density dependent all-optical femtosecond
time resolved study of the spin-density wave state in iron-based
superconductors. The destruction and recovery dynamics are measured by means of
the standard and a multi-pulse pump-probe technique. The experimental data are
analyzed and interpreted in the framework of an extended three temperature
model. The analysis suggests that the optical-phonons energy-relaxation plays
an important role in the recovery of almost exclusively electronically driven
spin density wave order.

34
The categories of this paper are: chem-ph
20
The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
24
The categories of this paper are: dg-ga
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The categories of this paper are: supr-con
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
14
The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
19
The categories of this paper are: eess
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph