标题： Kagome 晶格上的环电流序 显示英文标题

标题： Loop current order on the kagome lattice

摘要： 最近在kagome材料中的发现揭示了它们承载奇异量子态的能力，包括有趣的电荷密度波（CDW）和超导性。 值得注意的是，积累的实验证据表明，在CDW内部存在时间反演对称性（TRS）的破缺，这暗示了长期以来追求的环电流序（LCO）的存在。 尽管进行了大量研究工作，但实现其模型化以及通过无偏多体模拟理解其机制仍然是既难以捉摸又具有挑战性的任务。在这项工作中，我们开发了一个用于自旋无kagome晶格上非局域相互作用的LCO微观模型，并利用无偏函数重正化群计算来探索所有两粒子散射通道中的有序趋势。 在van Hove填充的情况下，我们确定了亚晶格干扰以抑制局域CDW序，使LCO、电荷键序和向列CDW态成为主要的竞争者。 值得注意的是，在强次近邻排斥的显著参数空间内，一种$2\times2$LCO 成为了多体基态，这是由于亚晶格特性与晶格几何之间的独特相互作用。 具有LCO的电子模型与Haldane模型有相似之处，并最终导致量子异常霍尔态。 我们还讨论了kagome金属的潜在实验意义。 显示英文摘要

摘要： Recent discoveries in kagome materials have unveiled their capacity to harbor exotic quantum states, including intriguing charge density wave (CDW) and superconductivity. Notably, accumulating experimental evidence suggests time-reversal symmetry (TRS) breaking within the CDW, hinting at the long-pursued loop current order (LCO). Despite extensive research efforts, achieving its model realization and understanding the mechanism through unbiased many-body simulations have remained both elusive and challenging.In this work, we develop a microscopic model for LCO on the spinless kagome lattice with non-local interactions, utilizing unbiased functional renormalization group calculations to explore ordering tendencies across all two-particle scattering channels. At the van Hove filling, we identify sublattice interference to suppress onsite CDW order, leaving LCO, charge bond and nematic CDW state as the main competitors. Remarkably, a $2\times2$ LCO emerges as the many-body ground state over a significant parameter space with strong second nearest-neighbor repulsion, stemming from the unique interplay between sublattice characters and lattice geometry. The resulting electronic model with LCO bears similarities to the Haldane model and culminates in a quantum anomalous Hall state. We also discuss potential experimental implications for kagome metals.