Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Unconventional electronic reconstruction in undoped (Ba,Sr)Fe$_2$As$_2$
  across the spin density wave transition   Through a systematic high resolution angle-resolved photoemission study of
the iron pnictide compounds (Ba,Sr)Fe$_2$As$_2$, we show that the electronic
structures of these compounds are significantly reconstructed across the spin
density wave ordering, which cannot be described by a simple folding scenario
of conventional density wave ordering. Moreover, we find that LDA calculations
with an incorporated suppressed magnetic moment of 0.5$\mu_{\tiny{\textrm{B}}}$
can match well the details in the reconstructed electronic structure,
suggesting that the nature of magnetism in the pnictides is more itinerant than
local, while the origin of suppressed magnetic moment remains an important
issue for future investigations.

31
The categories of this paper are: ao-sci
16
The categories of this paper are: stat
14
The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
17
The categories of this paper are: q-fin
12
The categories of this paper are: nucl-th
21
The categories of this paper are: adap-org
28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
9
The categories of this paper are: nlin
24
The categories of this paper are: dg-ga
22
The categories of this paper are: chao-dyn
3
The categories of this paper are: physics
6
The categories of this paper are: astro-ph
32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol