Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nematicity from mixed S_{+-} + d_{x^2-y^2} states in iron-based
  superconductors   We demonstrate that in iron-based superconductors, the extended S_{+-} SC
state coexists with the d_{x^2-y^2} state under generic conditions. The mixed
S_{+-} + d_{x^2-y^2} SC is a natural nematic state in which the tetragonal
symmetry C_4 is broken to C_2 explaining puzzling findings of nematic SC in
FeSe films [Science 332, 1410 (2011)]. Moreover, we report the possibility of a
first order transition at low-T from the nematic S_{+-} + d_{x^2-y^2} state to
the pure d_{x^2-y^2} state induced by the Zeeman magnetic field proposing an
original experimental strategy for identifying our mixed nematic state in FeSe
films. Extrapolating our findings, we argue that nematicity in non
superconducting states of underdoped and undoped pnictides may reflect mixed
S_{+-} + d_{x^2-y^2} Density Wave states.

11
The categories of this paper are: hep-lat
19
The categories of this paper are: eess
7
The categories of this paper are: hep-th
28
The categories of this paper are: alg-geom
32
The categories of this paper are: atom-ph
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
36
The categories of this paper are: cmp-lg
6
The categories of this paper are: astro-ph
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
25
The categories of this paper are: patt-sol
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
21
The categories of this paper are: adap-org