Neutron spin resonance as a probe of Fermi surface nesting and superconducting gap symmetry in Ba$_{0.67}$K$_{0.33}$(Fe$_{1-x}$Co$_{x}$)$_{2}$As$_{2}$

Rui Zhang; Weiyi Wang; Thomas Maier; Meng Wang; Matthew B. Stone; Songxue Chi; Barry Winn; Pengcheng Dai

doi:10.1103/PhysRevB.98.060502

paper

Neutron spin resonance as a probe of Fermi surface nesting and superconducting gap symmetry in Ba $_{0.67}$ K $_{0.33}$ (Fe $_{1 - x}$ Co $_{x}$ ) $_{2}$ As $_{2}$

arXiv:1808.06108 · doi:10.1103/PhysRevB.98.060502

Abstract

We use inelastic neutron scattering to study energy and wave vector dependence of the superconductivity-induced resonance in hole-doped Ba $_{0.67}$ K $_{0.33}$ (Fe $_{1 - x}$ Co $_{x}$ ) $_{2}$ As $_{2}$ ( $x = 0, 0.08$ with $T_{c} \approx 37, 28$ K, respectively). In previous work on electron-doped Ba(Fe $_{0.963}$ Ni $_{0.037}$ ) $_{2}$ As $_{2}$ ( $T_{N} = 26$ K and $T_{c} = 17$ K), the resonance is found to peak sharply at the antiferromagnetic (AF) ordering wave vector $Q_{AF}$ along the longitudinal direction, but disperses upwards away from $Q_{AF}$ along the transverse direction. For hole doped $x = 0, 0.08$ without AF order, we find that the resonance displays ring-like upward dispersion away from $Q_{AF}$ along both the longitudinal and transverse directions. By comparing these results with calculations using the random phase approximation, we conclude that the dispersive resonance is a direct signature of isotropic superconducting gaps arising from nested hole-electron Fermi surfaces.

5 pages, 4 figures

Neutron spin resonance as a probe of Fermi surface nesting and superconducting gap symmetry in Ba $_{0.67}$ K $_{0.33}$ (Fe $_{1 - x}$ Co $_{x}$ ) $_{2}$ As $_{2}$

Abstract

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Neutron spin resonance as a probe of Fermi surface nesting and superconducting gap symmetry in Ba0.67​K0.33​(Fe1−x​Cox​)2​As2​

Abstract

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Cited by in corpus (11)

Neutron spin resonance as a probe of Fermi surface nesting and superconducting gap symmetry in Ba $_{0.67}$ K $_{0.33}$ (Fe $_{1 - x}$ Co $_{x}$ ) $_{2}$ As $_{2}$