谷螺旋超导性由排斥和量子几何驱动：应用于时间反演对称菱面体石墨烯
Valley-Helical Superconductivity Driven by Repulsion and Quantum Geometry: Applications to Time-Reversal Symmetric Rhombohedral Graphene
浏览论文内容
中文总结 AI 辅助
本研究提出谷螺旋超导机制，通过Kohn-Luttinger排斥在时间反演对称菱面体石墨烯中实现手性配对，并预测了可区分的拓扑边界模式与磁响应。
中文摘要 AI 辅助
受最近在谷极化石墨烯和过渡金属二硫化物体系中手性超导实验迹象的启发，我们研究了在缺乏谷极化或时间反演对称性破缺的情况下手性配对的可能性。对于两个谷中具有相反贝里曲率的系统，我们发现过度屏蔽的排斥（即Kohn-Luttinger机制）确实可以在每个谷中诱导相反手性的配对，产生谷螺旋态。此外，尽管只有谷间配对态具有弱耦合不稳定性，但在中等耦合强度下，谷螺旋态可以胜过更传统的谷间配对态。利用时间反演对称菱面体石墨烯的现实模型，我们发现存在广泛的填充范围和位移场区域，其中谷螺旋超导占主导。这发生在我们考虑的所有层数（4≤N≤8）中。我们表明，谷螺旋态可以展示拓扑投影的边界模式、不寻常的磁响应以及交织的Kekulé类键序；这些特征可用于将它们与更传统的超导体区分开来。
英文摘要
Motivated by the recent experimental signatures of chiral superconductivity in valley-polarized graphene- and transition-metal-dichalcogenide-based systems, we investigate the possibility of chiral pairing in the absence of valley polarization or time-reversal symmetry breaking. For systems with opposite Berry curvature in the two valleys, we find that overscreened repulsion (i.e., the Kohn-Luttinger mechanism) can indeed induce pairing of opposite chiralities in each valley, producing a valley-helical state. Moreover, the valley-helical state can outcompete more conventional intervalley paired states at intermediate coupling, despite only the latter having a weak-coupling instability. Using a realistic model of time-reversal-symmetric rhombohedral graphene, we find extended ranges of fillings and displacement fields with dominant valley-helical superconductivity. This occurs for all layer numbers considered here, $4\leq N\leq 8$. We show that the valley-helical states can display topologically projected edge modes, unusual magnetic responses, and intertwined Kekulé-like bond-order; features that can be used to distinguish them from more conventional superconductors.
发表机构
- Stanford University（斯坦福大学）
- California Institute of Technology（加州理工学院）
机构由 AI 辅助整理，请以论文原文为准。
