Electronic band structure and momentum dependence of the superconducting gap in Ca1−xNaxFe2As2from angle-resolved photoemission spectroscopy

2012/11/19 by D. V. Evtushinsky, V. B. Zabolotnyy, Luminita Harnagea +14 · 2 citations
Materials Science · Physics and Astronomy · #Iron-based superconductors research #cond-mat.supr-con

paper · pdf · doi:10.1103/physrevb.87.094501

published as Phys. Rev. B 87, 094501 (2013) · first ARPES on CNFA

arxiv created 2012/11/19 · openalex publication_date 2013/03/04 · arxiv updated 2013/03/18 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

Electronic structure of newly synthesized single crystals of calcium iron arsenide doped with sodium with T_c ranging from 33 to 14 K has been determined by angle-resolved photoemission spectroscopy (ARPES). The measured band dispersion is in general agreement with theoretical calculations, nonetheless implies absence of Fermi-surface nesting at an antiferromagnetic vector. A clearly developing below T_c strongly band-dependant superconducting gap has been revealed for samples with various doping levels. The BCS ratio for optimal doping, 2\ensuremathΔ/k_BT_c=5.5, is substantially smaller than the numbers observed for related compounds.

Citations

• Properties of boson-exchange superconductors
• Observation of Fermi-surface–dependent nodeless superconducting gaps in Ba 0.6 K 0.4 Fe 2 As 2

Cited by

• Observation of Strong-Coupling Pairing with Weakened Fermi-Surface Nesting at Optimal Hole Doping in Ca 0.33 Na 0.67 Fe2As 2
• Lower critical field and SNS-Andreev spectroscopy of 122-arsenides: Evidence of nodeless superconducting gap

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