Observation of an isotropic superconducting gap at the Brillouin zone center of Tl$_{0.63}$K$_{0.37}$Fe$_{1.78}$Se$_2$

We performed a high-resolution angle-resolved photoemission spectroscopy study on superconducting (SC) Tl $_{0.63}$ K $_{0.37}$ Fe $_{1.78}$ Se $_{2}$ ( $T_{c} = 29$ K) in the whole Brillouin zone (BZ). In addition to a nearly isotropic $\sim$ 8.2 meV 2-dimensional (2D) SC gap ( $2 Δ / k_{B} T_{c} \sim 7$ ) on quasi-2D electron Fermi surfaces (FSs) located around M $(π, 0, 0)$ -A $(π, 0, π)$ , we observe a $\sim 6.2$ meV isotropic SC gap ( $2 Δ / k_{B} T_{c} \sim 5$ ) on the Z-centered electron FS that rules out any d-wave pairing symmetry and rather favors an s-wave symmetry. All isotropic SC gap amplitudes can be fit by a single gap function derived from a local strong coupling approach suggesting an enhancement of the next-next neighbor exchange interaction in the ferrochalcogenide superconductors.

Observation of an isotropic superconducting gap at the Brillouin zone center of Tl $_{0.63}$ K $_{0.37}$ Fe $_{1.78}$ Se $_{2}$

文献摘要

讨论

讲解博客

AI智能校验

Observation of an isotropic superconducting gap at the Brillouin zone center of Tl $_{0.63}$ K $_{0.37}$ Fe $_{1.78}$ Se $_{2}$

文献摘要

讨论

讲解博客

AI智能校验

Observation of an isotropic superconducting gap at the Brillouin zone center of Tl0.630.63​K0.370.37​Fe1.781.78​Se22​

文献摘要

讨论

|讲解博客

|AI智能校验

Observation of an isotropic superconducting gap at the Brillouin zone center of Tl0.630.63​K0.370.37​Fe1.781.78​Se22​

文献摘要

讨论

|讲解博客

|AI智能校验

Observation of an isotropic superconducting gap at the Brillouin zone center of Tl $_{0.63}$ K $_{0.37}$ Fe $_{1.78}$ Se $_{2}$

讲解博客

AI智能校验

Observation of an isotropic superconducting gap at the Brillouin zone center of Tl $_{0.63}$ K $_{0.37}$ Fe $_{1.78}$ Se $_{2}$

讲解博客

AI智能校验