Microwave conductivity in the ferropnictides with specific application to Ba1-xKxFe2As2

Article

关键词: ELECTRON-PHONON INTERACTION;    INELASTIC-SCATTERING RATE;    OPTICAL CONDUCTIVITY;    PENETRATION-DEPTH;    SYMMETRY;    GAP;    SUPERCONDUCTORS;    YBA2CU3O7-DELTA;    ANISOTROPY;    MODEL;   

DOI  :  10.1103/PhysRevB.80.174526

来源: SCIE

【 摘 要 】

We calculate the microwave conductivity of a two band superconductor with s(+/-) gap symmetry. Inelastic scattering is included approximately in a BCS model augmented by a temperature-dependent quasiparticle scattering rate assumed, however, to be frequency independent. The possibility that the s-wave gap on one or the other of the electron or hole pockets is anisotropic is explored including cases with and without gap nodes on the Fermi surface. A comparison of our BCS results with those obtained in the two-fluid model is provided as well as with the case of the cuprates where the gap has d-wave symmetry and with experimental results in Ba1-delta K delta Fe2As2. The presently available microwave conductivity data in this material provides strong evidence for large anisotropies in the electron pocket s-wave gap. While a best fit favors a gap with nodes on the Fermi surface this disagrees with some but not all penetration-depth measurements which would favor a nodeless gap as do also thermal-conductivity and nuclear-magnetic-resonance data.

【 授权许可】

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