Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Topological surface states and Andreev bound states in superconducting
  iron pnictides   The nontrivial topology of the electronic structure of iron pnictides can
lead to the appearance of surface states. We study such states in various strip
geometries with a focus on the superconducting phase. In the presence of
unconventional superconducting pairing with $s_\pm$-wave gap structure, the
topological states are quite robust and partly remain in the superconducting
gap. Furthermore, Andreev bound states appear, which coexist with the
topological states for small superconducting gaps and merge with them for
larger gap values. The bulk and surface dispersions are obtained from exact
diagonalization for two-orbital and five-orbital models in strip geometries.

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The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
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The categories of this paper are: ao-sci
23
The categories of this paper are: solv-int
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The categories of this paper are: nucl-ex
18
The categories of this paper are: econ
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
34
The categories of this paper are: chem-ph
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
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The categories of this paper are: hep-lat
0
The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th