English

Are there nodes in LaFePO, BaFe$_2$(AsP)$_2$, and KFe$_2$As$_2$ ?

Superconductivity 2015-06-04 v2

Abstract

We reexamined the experimental evidences for the possible existence of the superconducting (SC) gap nodes in the three most suspected Fe-pnictide SC compounds: LaFePO, BaFe2_2(As0.67_{0.67}P0.33_{0.33})2_2, and KFe2_2As2_2. We showed that while the TT-linear temperature dependence of the penetration depth λ(T)\lambda(T) of these three compounds indicate extremely clean nodal gap superconductors, the thermal conductivity data limT,H0κS(H,T)/T\lim_{T,H \rightarrow 0} \kappa_S (H,T)/T unambiguously showed that LaFePO and BaFe2_2(As0.67_{0.67}P0.33_{0.33})2_2 are extremely dirty, while KFe2_2As2_2 can be clean. This apparently conflicting experimental data casts a serious doubt on the nodal gap possibility on LaFePO and BaFe2_2(As0.67_{0.67}P0.33_{0.33})2_2.

Keywords

Cite

@article{arxiv.1204.0212,
  title  = {Are there nodes in LaFePO, BaFe$_2$(AsP)$_2$, and KFe$_2$As$_2$ ?},
  author = {Yunkyu Bang},
  journal= {arXiv preprint arXiv:1204.0212},
  year   = {2015}
}

Comments

11 pages, 5 figures A new section "4. Remark on the quantum oscillation (QO) experiments" is added