Although strong electronic correlations are known to be responsible for some highly unusual behaviors of solids such as metal-insulator transitions, magnetism, and even high-temperature superconductivity, their interplay with recently discovered topological states of matter awaits a full exploration. Here, we use a modern electronic structure method, combining the density functional theory of band electrons with dynamical self-energies of strongly correlated states, to predict that two well-known phases of actinide compound UNiSn, a paramagnetic semiconducting and antiferromagnetic metallic, correspond to topological insulator (TI) and Weyl semimetal (WSM) phases of topological quantum matter. Thus, the famous unconventional insulator-metal transition observed in UNiSn is also a TI-to-WSM transition. Driven by a strong hybridization between U $f$-electron multiplet transitions and band electrons, multiple energy gaps open up in the single-particle spectrum whose topological physics is revealed using the calculation of $Z_2$ invariants in the strongly correlated regime. A simplified physical picture of these phenomena is provided based on a periodic Anderson model of strong correlations and multiple band inversions that occur in this fascinating compound. Studying the topology of interacting electrons reveals interesting opportunities for finding exotic phase transitions in strongly correlated systems.

中文翻译：

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高度相关的System系元素UNiSn中的拓扑绝缘体到Weyl半金属的过渡

尽管众所周知，强电子相关性是造成固体某些极不正常行为的原因，例如金属-绝缘体跃迁，磁性，甚至是高温超导性，但它们与最近发现的物质拓扑状态的相互作用尚待全面研究。在这里，我们使用现代电子结构方法，将带电子的密度泛函理论与强相关态的动态自能相结合，以预测that系化合物UNiSn的两个众所周知的相，即顺磁性半导体和反铁磁性金属，对应于拓扑量子物质的拓扑绝缘体（TI）和Weyl半金属（WSM）相。因此，在UNiSn中观察到的著名的非常规绝缘体-金属过渡也是从TI到WSM的过渡。在U与U之间强力杂交的驱动下$F$-电子多重跃迁和能带电子，在单粒子光谱中打开了多个能隙，通过计算，可以揭示其拓扑物理 ${ž}_{\mathrm{2个}}$高度相关的体制中的不变式。这些现象的简化物理图像是基于在这种引人入胜的化合物中发生的强相关性和多频带反转的周期性安德森模型提供的。研究相互作用电子的拓扑结构揭示了在强相关系统中寻找奇异相变的有趣机会。