DMRG揭示的单谷中排斥驱动的$p - i p$超导性
Repulsion-Driven $p - i p$ Superconductivity in a Single Valley Revealed by DMRG
- Department of Physics and Astronomy, University of California, Irvine（加州大学尔湾分校物理与天文学系）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
通过DMRG计算，发现排斥驱动的单谷狄拉克费米子可形成稳健的$p-ip$拓扑超导，其源于非平凡量子几何，而非色散细节，为拓扑超导提供新平台。
AI中文摘要：
我们展示了由排斥驱动的单种狄拉克费米子的拓扑超导性，这一研究受到在菱面体石墨烯等二维材料中观察到的谷极化相的启发。利用在宽度至八的圆柱上的Qi-Wu-Zhang晶格模型上进行密度矩阵重整化群计算，我们发现了一个稳健的无自旋手性$p$-波超导相。配对在低掺杂时即开始，因此发生在一个小的、近似各向同性的费米口袋上，并且不与色散的具体细节或各向异性相关，而似乎与能带的非平凡量子几何相关。事实上，超导序参量的缠绕方向与形成母态的反常霍尔金属的缠绕方向相反（“$p-ip$”），这与最近从弱耦合计算中得出的预期一致。在较大掺杂时，我们发现零动量配对旁边发展出配对密度波分量。我们的工作表明，强排斥、母态中时间反演对称性的缺失以及非平凡的量子几何的结合，构成了实现拓扑超导性的一个有前景的平台。
英文摘要：
We demonstrate repulsion-driven topological superconductivity of a single species of Dirac fermions, motivated by valley-polarized phases observed in two-dimensional materials such as rhombohedral graphene. Using density-matrix renormalization group calculations on the Qi-Wu-Zhang lattice model on cylinders of width up to eight, we find a robust phase of spinless chiral $p$-wave superconductivity. Pairing already starts at low doping and thus occurs on a small, nearly isotropic Fermi pocket, and is therefore not tied to the particular details or anisotropy of the dispersion but instead seems tied to the non-trivial quantum geometry of the bands. In fact, the winding of the superconductor order parameter is opposite ("$p-ip$") to that of the anomalous Hall metal which forms the parent state, in agreement with expectations recently derived from weak coupling calculations. At larger doping, we find that a pair-density-wave component develops alongside zero-momentum pairing. Our work shows that the combination of strong repulsion, absence of time-reversal in the parent state, and non-trivial quantum geometry form a promising platform to realize topological superconductivity.
