Universal Heat Conduction in the Iron Arsenide Superconductor KFe2As2: Evidence of a d-Wave State
| Title | Universal Heat Conduction in the Iron Arsenide Superconductor KFe2As2: Evidence of a d-Wave State |
| Publication Type | Journal Article |
| Year of Publication | 2012 |
| Authors | Reid JP, Tanatar MA, Juneau-Fecteau A, Gordon RT, de Cotret SR, Doiron-Leyraud N, Saito T, Fukazawa H, Kohori Y, Kihou K, Lee CH, Iyo A, Eisaki H, Prozorov R, Taillefer L |
| Journal Title | Physical Review Letters |
| Volume | 109 |
| Pages | 087001 |
| Date Published | 08 |
| Type of Article | Article |
| ISBN Number | 0031-9007 |
| Accession Number | WOS:000307712400010 |
| Keywords | quasi-particle transport, thermal-conductivity, vortex state, yba2cu3o6.9 |
| Abstract | The thermal conductivity kappa of the iron arsenide superconductor KFe2As2 was measured down to 50 mK for a heat current parallel and perpendicular to the tetragonal c axis. A residual linear term at T -> 0, kappa(0)/T is observed for both current directions, confirming the presence of nodes in the superconducting gap. Our value of kappa(0)/T in the plane is equal to that reported by Dong et al. [Phys. Rev. Lett. 104, 087005 (2010)] for a sample whose residual resistivity rho(0) was 10 times larger. This independence of kappa(0)/T on impurity scattering is the signature of universal heat transport, a property of superconducting states with symmetry-imposed line nodes. This argues against an s-wave state with accidental nodes. It favors instead a d-wave state, an assignment consistent with five additional properties: the magnitude of the critical scattering rate Gamma(c) for suppressing T-c to zero; the magnitude of kappa(0)/T, and its dependence on current direction and on magnetic field; the temperature dependence of kappa(T). |
| URL | <Go to ISI>://WOS:000307712400010 |
| DOI | 10.1103/PhysRevLett.109.087001 |
| Alternate Journal | Phys. Rev. Lett. |
