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arXiv 1906.01633cond-mat.supr-con
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铜氧化物超导体赝能隙相中的分形对密度波

Fractionalized pair density wave in the pseudo-gap phase of cuprate superconductors

D. Chakraborty, M. Grandadam, M. H. Hamidian, J. C. S. Davis, Y. Sidis, C. Pépin

摘要:

铜氧化物超导体中神秘的伪能隙(PG)相在过去的30年里一直是人们深入研究的主题,但对于它的起源却没有明确的共识。由于最近在拉曼光谱中观察到的前体在电荷通道中,在超导通道中的前体的众所周知的事实之上,我们在这里提出了一个新的想法:PG是通过希格斯机制形成的,其中两种预制对,在粒子-粒子和粒子-空穴通道中,通过冻结它们的全局相位而纠缠在一起。值得注意的是,这种纠缠相当于将库珀对密度波(PDW)分解为基本部分;粒子-空穴对,引起密度调制和电流调制,粒子-粒子对应物,导致库珀对的形成。从这个角度来看,“细分PDW”成为围绕伪间隙形成的中心对象。“锁定”的电荷和超导模式之间的相位给出了一个独特的解释不寻常的全球相位相干的短程电荷调制,观察到以下$T_{c}$的相敏扫描隧道显微镜(STM)。一个简单的微观模型使我们能够估计的平均场值的前体间隙在每个通道和PG的能量尺度,并将它们与拉曼散射光谱中观察到的值进行比较。我们还讨论了在PG阶段的订单的多样性的可能性,并给出了一个概述的相图。

英文摘要:

The mysterious pseudo-gap (PG) phase of cuprate superconductors has been the subject of intense investigation over the last thirty years, but without a clear agreement about its origin. Owing to a recent observation in Raman spectroscopy, of a precursor in the charge channel, on top of the well known fact of a precursor in the superconducting channel, we present here a novel idea: the PG is formed through a Higgs mechanism, where two kinds of preformed pairs, in the particle-particle and particle-hole channels, become entangled through a freezing of their global phase. Remarkably, this entanglement is equivalent to fractionalizing a Cooper pair density wave (PDW) into its elementary parts; the particle-hole pair, giving rise to both density modulations and current modulations, and the particle-particle counterpart, leading to the formation of Cooper pairs. From this perspective, the "fractionalized PDW" becomes the central object around the formation of the pseudo-gap. The "locking" of phases between the charge and superconducting modes gives a unique explanation for the unusual global phase coherence of short-range charge modulations, observed below $T_{c}$ on phase sensitive scanning tunneling microscopy (STM). A simple microscopic model enables us to estimate the mean-field values of the precursor gaps in each channel and the PG energy scale, and to compare them to the values observed in Raman scattering spectroscopy. We also discuss the possibility of a multiplicity of orders in the PG phase and give an overview of the phase diagram.

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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