二维离子材料中基于简并$p$ -轨道的实在平带模型
Realistic flat-band model based on degenerate $p$-orbitals in two-dimensional ionic materials
摘要：
虽然人们已经提出了几种设计电子平带的理论模型，但在二维原子晶体中还缺乏明确的实验实现。在这里，我们提出了一个新的和现实的平带模型的基础上的三重简并$p$ -轨道在二维离子材料。我们的理论分析和第一性原理计算表明，所提出的平带可以在碱金属卤化物和金属碳族化合物的1 T层状材料中实现。前者中的一些在理论上被预测为作为层状材料是稳定的（例如，K $_2$ S），并且后者中的一些已经在先前的工作中实验性地制造（例如，Gd $_2$ CCl $_2$）。更有趣的是，平带部分填充在K $_2$ S单层和石墨烯层的异质结构中。实验上制备的Gd $_2$ CCl $_2$单层膜在铁磁态下可实现自旋极化近平带。我们的理论模型与材料预测一起为研究平带和相关的奇异量子相提供了一个现实的平台。
英文摘要：
Though several theoretical models have been proposed to design electronic flat-bands, the definite experimental realization in two-dimensional atomic crystal is still lacking. Here we propose a novel and realistic flat-band model based on threefold degenerate $p$-orbitals in two-dimensional ionic materials. Our theoretical analysis and first-principles calculations show that the proposed flat-band can be realized in 1T layered materials of alkali-metal chalogenides and metal-carbon group compounds. Some of the former are theoretically predicted to be stable as layered materials (e.g., K$_2$S), and some of the latter have been experimentally fabricated in previous works (e.g., Gd$_2$CCl$_2$). More interestingly, the flat-band is partially filled in the heterostructure of a K$_2$S monolayer and graphene layers. The spin polarized nearly flat-band can be realized in the ferromagnetic state of a Gd$_2$CCl$_2$ monolayer, which has been fabricated in experiments. Our theoretical model together with the material predictions provide a realistic platform for the study of flat-bands and related exotic quantum phases.
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。
