Superconductivity and phonon self-energy effects in Fe1+yTe0.6Se0.4
Superconductivity and phonon self-energy effects in Fe1+yTe0.6Se0.4
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DOI：
10.1103/physrevresearch.2.013373
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发表时间：
2019-11
影响因子：
4.2
通讯作者：
S. F. Wu;A. Almoalem;I. Feldman;A. Lee;A. Kanigel;Girsh Blumberg;Girsh Blumberg
中科院分区：
文献类型：
--
作者：
S. F. Wu;A. Almoalem;I. Feldman;A. Lee;A. Kanigel;Girsh Blumberg;Girsh Blumberg
利用偏振分辨拉曼光谱研究了Fe $_{1+y}$ Te $_{0.6}$ Se $_{0.4}$含$T_c=14$ K的多带超导体。在超导态深处，我们在$XY$ （$B_{2g}$）散射几何中探测到45cm $^{-1}$ （$2\Delta=5.6$ meV）处的对断裂激发，这与ARPES在具有$d_{xz}/d_{yz}$特征的类空穴费米口袋上显示的超导间隙能（3 meV）的两倍一致。我们分析了$B_{1g}$ （Fe）声子的超导诱导声子自能效应，并估计了电子-声子耦合常数$\lambda^\Gamma \approx 0.026$，该常数不足以解释$T_c=14$ K的超导性。
We study Fe$_{1+y}$Te$_{0.6}$Se$_{0.4}$ multi-band superconductor with $T_c=14$K by polarization-resolved Raman spectroscopy. Deep in the superconducting state, we detect pair-breaking excitation at 45cm$^{-1}$ ($2\Delta=5.6$meV) in the $XY$($B_{2g}$) scattering geometry, consistent with twice of the superconducting gap energy (3 meV) revealed by ARPES on the hole-like Fermi pocket with $d_{xz}/d_{yz}$ character. We analyze the superconductivity induced phonon self-energy effects for the $B_{1g}$(Fe) phonon and estimate the electron-phonon coupling constant $\lambda^\Gamma \approx 0.026$, which is insufficient to explain superconductivity with $T_c=14$K.