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arXiv 1406.6086cond-mat.str-el
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电子-声子相互作用在磁驱动超导机制中的作用

Role of electron-phonon interaction in a magnetically driven mechanism for superconductivity

Hassan Bakrim, Claude Bourbonnais

摘要:

本文利用重整化群方法研究了自旋涨落驱动的准一维电子系统中声子相互作用对d波超导性的影响。本文计算了在任意温度、声子频率和费米面反嵌套条件下,紧束缚电子-声子相互作用对自旋密度波和d波超导不稳定性线的影响,确定了弱反嵌套条件下自旋密度波序因键序波或Peierls态的形成而不稳定的电子-声子耦合强度范围。我们证明了自旋密度波和d波超导临界温度的正同位素效应的存在,它与两种不稳定性合并的量子临界点的反嵌套距离成比例。我们挑出一个低的声子频率区的键序波排序引起的三重态f波超导嵌套蚀变下,与两个排序显示负同位素效应。我们还研究了在超导电性之上的金属相中扩展量子临界起源处自旋涨落的电子-声子强化。我们的研究结果的影响,如Bechgaard盐的准一维有机导体Peierls扭曲是不存在的,超导性出现在压力下的自旋密度波状态附近的强调。

英文摘要:

We use the renormalization group method to examine the effect of phonon mediated interaction on d-wave superconductivity, as driven by spin fluctuations in a quasi-one-dimensional electron system. The influence of a tight-binding electron-phonon interaction on the spin-density-wave and d-wave superconducting instability lines is calculated for arbitrary temperature, phonon frequency and antinesting of the Fermi surface.The domain of electron-phonon coupling strength where spin-density-wave order becomes unstable against the formation of a bond-order-wave or Peierls state is determined at weak antinesting. We show the existence of a positive isotope effect for spin-density-wave and d-wave superconducting critical temperatures which scales with the antinesting distance from quantum critical point where the two instabilities merge. We single out a low phonon frequency zone where the bond-oder-wave ordering gives rise to triplet f-wave superconductivity under nesting alteration, with both orderings displaying a negative isotope effect. We also study the electron-phonon strengthening of spin fluctuations at the origin of extended quantum criticality in the metallic phase above superconductivity. The impact of our results on quasi-one-dimensional organic conductors like the Bechgaard salts where a Peierls distortion is absent and superconductivity emerges near a spin-density-wave state under pressure is emphasized.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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