Phase transition beneath the superconducting dome in BaFe[subscript 2](As[subscript 1-x]P[subscript x])[subscript 2]

We present a theory for the large suppression of the superfluid density ρ[subscript s] in BaFe[subscript 2](As[subscript 1−x]P[subscript x])[subscript 2] in the vicinity of a putative spin-density wave quantum critical point at a P doping, x = x[subscript c]. We argue that the transition becomes wea...

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Bibliographic Details
Main Authors: Chowdhury, Debanjan, Orenstein, J., Sachdev, Subir, Todadri, Senthil
Other Authors: Massachusetts Institute of Technology. Department of Physics
Format: Article
Language:English
Published: American Physical Society 2015
Online Access:http://hdl.handle.net/1721.1/98230
https://orcid.org/0000-0003-4203-4148
Description
Summary:We present a theory for the large suppression of the superfluid density ρ[subscript s] in BaFe[subscript 2](As[subscript 1−x]P[subscript x])[subscript 2] in the vicinity of a putative spin-density wave quantum critical point at a P doping, x = x[subscript c]. We argue that the transition becomes weakly first order in the vicinity of x[subscript c], and disorder induces puddles of superconducting and antiferromagnetic regions at short length scales; thus, the system becomes an electronic microemulsion. We propose that frustrated Josephson couplings between the superconducting grains suppress ρ[subscript s]. In addition, the presence of “normal” quasiparticles at the interface of the frustrated Josephson junctions will give rise to a highly nontrivial feature in the low-frequency response in a narrow vicinity around x[subscript c]. We propose a number of experiments to test our theory.