Based on first-principles calculations, we demonstrate that the recently-synthesized 2D organometallic framework consisting of Au atoms and 1,3,5-triethynylbenzene (Au-TEB) is a magnetic 2D organic topological insulator (OTI). The charge transfer and covalent bonding character lead to ferromagnetism and half-metallicity in the framework, and the weak spin-orbit coupling (SOC) of C p_z orbitals mediated by Au d orbitals opens modest bandgaps in the vicinity of the Fermi level. Moreover, using tight-binding model simulations, we further characterize the nonzero Chern number and edge states of Au-TEB to confirm its topological nontriviality that remains intact when the framework is supported on an insulating substrate, and applying an external strain can increase the magnitude of SOC gaps, leading to an enhanced topological nontriviality. Our results suggest that the Au-TEB organometallic framework is promising for the potential applications in quantum spintronics with the merits of low cost and easy synthesis.

中文翻译：

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磁性二维有机拓扑绝缘体：Au–1,3,5-三乙炔基苯骨架

基于第一性原理计算，我们证明了由Au原子和1,3,5-三乙炔基苯（Au-TEB）组成的最近合成的2D有机金属骨架是磁性2D有机拓扑绝缘体（OTI）。电荷转移和共价键特征导致框架中的铁磁性和半金属性，以及Au d介导的C p _z轨道的弱自旋轨道耦合（SOC）轨道在费米能级附近打开了适度的带隙。此外，使用紧密绑定模型模拟，我们进一步表征了Au-TEB的非零Chern数和边缘状态，以确认当框架支撑在绝缘基板上时其拓扑非平凡性保持不变，并且施加外部应变可以增加幅度SOC间隙的变化，导致拓扑非平凡性增强。我们的结果表明，Au-TEB有机金属框架具有低成本和易于合成的优点，有望在量子自旋电子学中得到潜在应用。