Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Multiorbital Spin Susceptibility in a Magnetically Ordered State -
  Orbital versus Excitonic Spin Density Wave Scenario   We present a general theory of multiorbital spin waves in magnetically
ordered metallic systems. Motivated by the itinerant magnetism of iron-based
superconductors, we compare the magnetic excitations for two different
scenarios: when the magnetic order either sets in on the on-site orbital level;
or when it appears as an electron-hole pairing between different bands of
electron and hole character. As an example we treat the two-orbital model for
iron-based superconductors. For small magnetic moments the spin excitations
look similar in both scenarios. Going to larger interactions and larger
magnetic moments, the difference between both scenarios becomes striking. While
in the excitonic scenario the spin waves form a closed structure over the
entire Brillouin zone and the particle-hole continuum is gapped, the spin
excitations in the orbital scenario can be treated as spin waves only in a
close vicinity to the ordering momenta. The origin of this is a gapless
electronic structure with Dirac cones which is a source of large damping. We
analyze our results in connection with recent neutron scattering measurements
and show that certain features of the orbital scenario with multiple order
parameters can be observed experimentally.

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The categories of this paper are: patt-sol
6
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: dg-ga
8
The categories of this paper are: hep-ex
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
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The categories of this paper are: hep-lat
0
The categories of this paper are: hep-ph
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The categories of this paper are: cmp-lg
20
The categories of this paper are: acc-phys
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The categories of this paper are: stat
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The categories of this paper are: chao-dyn