Impurity effects on the spin excitation spectra in a d-wave superconductor
Impurity effects on the spin excitation spectra in a d-wave superconductor
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DOI：
10.1103/physrevb.58.2895
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发表时间：
1998-08
影响因子：
3.7
通讯作者：
Jian-xin Li;W. Yin;C. Gong
中科院分区：
文献类型：
--
作者：
Jian-xin Li;W. Yin;C. Gong
本文用自洽的$t$-矩阵近似方法研究了d_{x^2-y^2}$波超导体中杂质对自旋激发谱的影响。结果表明，杂质自能的作用是使共振峰向低频移动，使共振峰展宽。而杂质顶点修正导致自旋能隙在杂质浓度范围内有一个宽的谱权，在此范围内没有观察到明显的共振峰。在低频区，杂质的引入仍然保留了带隙特征。对这两种效应进行了解释，发现其结果与YBa_{2}（Cu_{1-x}Zn_{x}）_{3}O_{6+y}的实验定性一致。
The effects of nonmagnetic impurity on the spin excitation spectra in a $d_{x^2-y^2}$-wave superconductor are examined, using the self-consistent $t$-matrix approximation. It is shown that the impurity self-energy acts to shift the position of the resonance peak to low frequencies and broaden the peak. While the impurity vertex correction causes a broad spectral weight in the spin gap at the impurity concentrations where no clear resonance peak is observed. The gaplike feature still remains in low frequency region upon the introduction of impurities. Incorporating these two effects, we find that the result is in qualitative agreement with experiments on YBa_{2}(Cu_{1-x}Zn_{x})_{3}O_{6+y}.