Observation of strong-coupling pairing with weakened Fermi-surface nesting at optimal hole doping in Ca$_{0.33}$Na$_{0.67}$Fe$_2$As$_2$

Y. -B. Shi; Y. -B. Huang; X. -P. Wang; X. Shi; A. van Roekeghem; W. -L. Zhang; N. Xu; P. Richard; T. Qian; E. D. L. Rienks; S. Thirupathaiah; K. Zhao; C. -Q. Jin; M. Shi; H. Ding

doi:10.1088/0256-307X/31/6/067403

paper

Observation of strong-coupling pairing with weakened Fermi-surface nesting at optimal hole doping in Ca $_{0.33}$ Na $_{0.67}$ Fe $_{2}$ As $_{2}$

arXiv:1402.5875 · doi:10.1088/0256-307X/31/6/067403

Abstract

We report an angle-resolved photoemission investigation of optimally-doped Ca $_{0.33}$ Na $_{0.67}$ Fe $_{2}$ As $_{2}$ . The Fermi surface topology of this compound is similar to that of the well-studied Ba $_{0.6}$ K $_{0.4}$ Fe $_{2}$ As $_{2}$ material, except for larger hole pockets resulting from a higher hole concentration per Fe atoms. We find that the quasi-nesting conditions are weakened in this compound as compared to Ba $_{0.6}$ K $_{0.4}$ Fe $_{2}$ As $_{2}$ . As with Ba $_{0.6}$ K $_{0.4}$ Fe $_{2}$ As $_{2}$ though, we observe nearly isotropic superconducting gaps with Fermi surface-dependent magnitudes. A small variation in the gap size along the momentum direction perpendicular to the surface is found for one of the Fermi surfaces. Our superconducting gap results on all Fermi surface sheets fit simultaneously very well to a global gap function derived from a strong coupling approach, which contains only 2 global parameters.

5 pages, 4 figures

Observation of strong-coupling pairing with weakened Fermi-surface nesting at optimal hole doping in Ca $_{0.33}$ Na $_{0.67}$ Fe $_{2}$ As $_{2}$

Abstract

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Observation of strong-coupling pairing with weakened Fermi-surface nesting at optimal hole doping in Ca0.33​Na0.67​Fe2​As2​

Abstract

References in corpus (12)

Cited by in corpus (2)

Observation of strong-coupling pairing with weakened Fermi-surface nesting at optimal hole doping in Ca $_{0.33}$ Na $_{0.67}$ Fe $_{2}$ As $_{2}$