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arXiv 2408.03056cond-mat.supr-con
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笼目超导体中2×2配对密度波的自洽理论

Self-consistent theory of $2\times2$ pair density waves in kagome superconductors

Meng Yao, Yan Wang, Da Wang, Jia-Xin Yin, Qiang-Hua Wang

AI总结:

本文通过自洽平均场理论在笼目晶格中提出由在键吸引相互作用和p型范霍夫奇点驱动的2×2 3Q配对密度波,发现其分为陈数C=0和C=±2两类,其中手性PDW无需自旋轨道耦合即可实现拓扑量子态,并预言了可实验检验的各向异性超导能隙和量子化横向热导率。

摘要:

配对密度波(PDW)是凝聚态物理前沿提出的一种引人注目的量子物态。然而,在微观模型中PDW的存在一直较为罕见。在本工作中,我们通过Ginzburg-Landau论证和自洽平均场理论,在笼目晶格上得到了由在键吸引配对相互作用以及p型范霍夫奇点附近不同布洛赫波函数所产生的新型2a0×2a0 PDW。携带三个独立波矢的PDW态,即所谓的3Q PDW,是无节点的,并分为两个拓扑类,其特征为陈数C=0或C=±2。手性(C=±2)PDW态呈现了一种罕见的由相互作用驱动的拓扑量子态,且无需自旋轨道耦合。最后,我们分析了这些PDW与电荷序交织时的稳定性与性质,并讨论了我们最小模型与笼目超导体近期实验观测的相关性。我们的理论不仅阐明了手性PDW的驱动力,还预言了动量空间中强各向异性的超导能隙结构以及量子化横向热导率,这些都可以在未来的实验中进行检验。

英文摘要:

Pair density wave (PDW) is an intriguing quantum matter proposed in the frontier of condensed matter physics. However, the existence of PDW in microscopic models has been rare. In this work, we obtain, by Ginzburg-Landau arguments and self-consistent mean field theory, novel $2a_0\times2a_0$ PDW on the kagome lattice arising from attractive on-bond pairing interactions and the distinct Bloch wave functions near the p-type van Hove singularity. The PDW state carrying three independent wave-vectors, the so-called 3Q PDW, is nodeless and falls into two topological classes characterized by the Chern number $C = 0$ or $C = \pm2$. The chiral ($C=\pm2$) PDW state presents a rare case of interaction driven topological quantum state without the requirement of spin-orbit coupling. Finally, we analyze the stabilities and properties of these PDWs intertwining with charge orders, and discuss the relevance of our minimal model to recent experimental observations in kagome superconductors. Our theory not only elucidates the driving force of the chiral PDW, but also predicts strongly anisotropic superconducting gap structure in the momentum space and quantized transverse thermal conductivity that can be tested in future experiments.

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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