Suppression of superconductivity by spin fluctuations
Suppression of superconductivity by spin fluctuations
复制标题
自旋涨落抑制超导性
DOI：
10.1088/1742-6596/2164/1/012013
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
Yamase Hiroyuki
中科院分区：
文献类型：
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作者：
Kazuhiro Nawa;Yoshinori Imai;Youhei Yamaji;Hideyuki Fujihara,Wakana Yamada;Ryotaro Takahashi;Takumi Hiraoka;Masato Hagihala;Shuki Torii;Takuya Aoyama;Takamasa Ohashi;Yasuhiro Shimizu;Hirotada Gotou;Masayuki Itoh;Kenya Ohgushi;and Taku J. Sat;M. Koshino;Yamase Hiroyuki
我们回顾了正方形晶格上一般电子系统中由自旋涨落所介导的超导不稳定性。我们使用标准的Eliashberg理论，考虑了电子的自能，保持了很好的动量分辨率，并在很低的温度下进行了数值计算，从而确定了超导的起始温度(SC)。我们发现，尽管超导不稳定性最终会在较低的温度下发生，但自旋涨落必然会对Sc的抑制做出贡献。这种自约束效应源于自旋涨落引起的排斥性配对相互作用，导致配对禁带的位相受挫，从而抑制了Sc。自约束效应是自旋涨落的一种特殊特征，当SC由吸引的配对相互作用驱动时，例如向列相涨落、轨道涨落和电子-声子耦合，不会发生自约束效应。
We revisit the superconducting instability mediated by spin fluctuations in generic electron systems on a square lattice. We employ the standard Eliashberg theory, include the electron self-energy, keep a fine momentum resolution, and achieve numerical calculations down to very low temperatures so that the onset temperature of superconductivity (SC) can be determined. We find that spin fluctuations necessarily contain a contribution to suppress SC even though the superconducting instability can eventually occur at lower temperatures. This self-restraint effect stems from the repulsive pairing interaction induced by spin fluctuations, which leads to phase frustration of the pairing gap and consequently the suppression of SC. The self-restraint effect is a special feature of spin fluctuations and does not occur when SC is driven by the attractive pairing interaction from, for example, nematic fluctuations, orbital fluctuations, and electron-phonon coupling.