Title: Spin-fluctuation glue disfavors high-critical temperature of superconductivity? Show Chinese title

Title: 自旋涨落胶子不利于高温超导性的出现？

Abstract: Antiferromagnetic fluctuations are believed to be a promising glue to drive high-temperature superconductivity especially in cuprates. Here, we perform a close inspection of the superconducting mechanism from spin fluctuations in the Eliashberg framework by employing a typical one-band model on a square lattice. While spin fluctuations can eventually drive superconductivity as is well established, we find that the superconducting tendency is suppressed substantially by a seemingly negligible contribution from a small momentum transfer far away from (pi,pi). This suppression comes from phase frustration of the pairing gap and is expected to be a general feature due to the repulsive pairing interaction of spin fluctuations. Furthermore, we find that the momentum dependence of the pairing gap largely deviates from the functional form of cos kx - cos ky, although this form is well established in cuprate superconductors. We argue that an instantaneous magnetic interaction plays the important role to understand high-critical temperature of superconductivity as well as the momentum dependence of the pairing gap. Show Chinese abstract

Abstract: 反铁磁涨落被认为是一种有前途的粘合剂，以推动高温超导性，特别是在铜氧化物中。 在这里，我们通过在正方形晶格上采用一个典型的单带模型，在Eliashberg框架中对自旋涨落中的超导机制进行仔细检查。 虽然自旋涨落最终可以驱动超导性，这是众所周知的，但我们发现，由于远离(pi,pi)的小动量转移的似乎可以忽略的贡献，超导趋势被显著抑制。 这种抑制来自于配对能隙的相位挫折，并且由于自旋涨落的排斥性配对相互作用，预计这将是一个普遍特征。 此外，我们发现配对能隙的动量依赖性与cos kx - cos ky的函数形式有很大偏差，尽管这一形式在铜氧化物超导体中已被广泛确立。 我们认为，瞬时磁相互作用在理解高临界温度的超导性以及配对能隙的动量依赖性方面起着重要作用。