摘要
The comprehensive low-temperature specific-heat C(T) data identify both an isotropic s-wave and extended s-wave order parameters coexisting in a superconducting single-crystal FeSe with T c = 8.11 K. The isotropic gap Δ 0 = 1.33 meV on the hole Fermi sheets and the extended s-wave gap Δ = Δ e(1+αcos2) with Δ e = 1.13 meV and α = 0.78 on the electron Fermi sheets. The extended s wave is rather anisotropic, but the low-energy quasiparticle excitations demonstrate no sign of the accidental nodes. The coefficient γ(H) manifesting the quasiparticle contribution to C is a nonlinear function of the applied magnetic field H in the mixed state in accord with the anisotropic multiorder parameters.
原文 | English |
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文章編號 | 220507 |
期刊 | Physical Review B - Condensed Matter and Materials Physics |
卷 | 84 |
發行號 | 22 |
DOIs | |
出版狀態 | Published - 27 12月 2011 |