Dynamical susceptibility of a near-critical nonconserved order parameter and quadrupole Raman response in Fe-based superconductors
Author(s)
Klein, Avraham; Lederer, Samuel; Chowdhury, Debanjan; Berg, Erez; Chubukov, Andrey
DownloadPhysRevB.98.041101.pdf (482.0Kb)
PUBLISHER_POLICY
Publisher Policy
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Terms of use
Metadata
Show full item recordAbstract
We analyze the dynamical response of a two-dimensional system of itinerant fermions coupled to a scalar boson ϕ, which undergoes a continuous transition towards nematic order with a d-wave form factor. We consider two cases: (a) when ϕ is a soft collective mode of fermions near a Pomeranchuk instability, and (b) when it is an independent critical degree of freedom, such as a composite spin order parameter. In both cases, the order parameter is not a conserved quantity and the d-wave fermionic polarization Π(q,Ω) remains finite even at q=0. The polarization Π(0,Ω) has similar behavior in the two cases, but the relations between Π(0,Ω) and the bosonic susceptibility χ(0,Ω) are different, leading to different forms of χ′′(0,Ω), as measured by Raman scattering. We compare our results with polarization-resolved Raman data for the Fe-based superconductors FeSe[subscript 1−x]S[subscript x],NaFe[subscript 1−x]Co[subscript x]As, and BaFe₂As₂.
Date issued
2018-07Department
Massachusetts Institute of Technology. Department of PhysicsJournal
Physical Review B
Publisher
American Physical Society
Citation
Klein, Avraham et al. "Dynamical susceptibility of a near-critical nonconserved order parameter and quadrupole Raman response in Fe-based superconductors." Physical Review B 98, 4 (July 2018): 041101(R) © 2018 American Physical Society
Version: Final published version
ISSN
2469-9950
2469-9969