paper

Phase transition beneath the superconducting dome in BaFe $_{2}$ (As $_{1 - x}$ P $_{x}$ ) $_{2}$

arXiv:1502.04122 · doi:10.1103/PhysRevB.92.081113

Abstract

We present a theory for the large suppression of the superfluid-density, $I ¨ _{s}$ , in BaFe $_{2}$ (As $_{1 - x}$ P $_{x}$ ) $_{2}$ in the vicinity of a putative spin-density wave quantum critical point at a P-doping, $x = x_{c}$ . We argue that the transition becomes weakly first-order in the vicinity of $x_{c}$ , and disorder induces puddles of superconducting and antiferromagnetic regions at short length-scales; thus the system becomes an electronic micro-emulsion. We propose that frustrated Josephson couplings between the superconducting grains suppress $I ¨ _{s}$ . In addition, the presence of `normal' quasiparticles at the interface of the frustrated Josephson junctions will give rise to a highly non-trivial feature in the low frequency response in a narrow vicinity around $x_{c}$ . We propose a number of experiments to test our theory.

4.5 pages, 4 figures; (v2) made some textual changes for increased clarity. This version also includes a new figure, supplementary material and updated references

Phase transition beneath the superconducting dome in BaFe2​(As1−x​Px​)2​

Abstract

Phase transition beneath the superconducting dome in BaFe $_{2}$ (As $_{1 - x}$ P $_{x}$ ) $_{2}$