Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Microscopic pairing fingerprint of the iron-based superconductor ${\rm
  Ba_{1-x}K_xFe_2As_2}$   Resolving the microscopic pairing mechanism and its experimental
identification in unconventional superconductors is among the most vexing
problems of contemporary condensed matter physics. We show that Raman
spectroscopy provides an avenue for this quest by probing the structure of the
pairing interaction at play in an unconventional superconductor. As we study
the spectra of the prototypical Fe-based superconductor ${\rm
Ba_{1-x}K_xFe_2As_2}$ for $0.22\le x \le 0.70$ in all symmetry channels, Raman
spectroscopy allows us to distill the leading $s$-wave state. In addition, the
spectra collected in the $B_{1g}$ symmetry channel reveal the existence of two
collective modes which are indicative of the presence of two competing, yet
sub-dominant, pairing tendencies of $d_{x^2-y^2}$ symmetry type. A
comprehensive functional Renormalization Group (fRG) and random-phase
approximation (RPA) study on this compound confirms the presence of the two
sub-leading channels, and consistently matches the experimental doping
dependence of the related modes. The synopsis of experimental evidence and
theoretical modelling supports a spin-fluctuation mediated superconducting
pairing mechanism.

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The categories of this paper are: econ
16
The categories of this paper are: stat
25
The categories of this paper are: patt-sol
5
The categories of this paper are: gr-qc
1
The categories of this paper are: cs
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
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The categories of this paper are: solv-int
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The categories of this paper are: atom-ph
6
The categories of this paper are: astro-ph
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The categories of this paper are: hep-th
15
The categories of this paper are: nucl-ex