论文标题
使用AB-Initio输入的扭曲多层系统的低能对称性汉密尔顿和哈伯德参数的构建
Construction of low-energy symmetric Hamiltonians and Hubbard parameters for twisted multilayer systems using ab-initio input
论文作者
论文摘要
在这项工作中介绍了用于获得扭曲多层系统的低能对称性紧密结合的哈密顿量的计算高效工作流程。我们将此方案应用于第一个魔术角扭曲双层石墨烯。作为初步步骤，Slater-Koster模型生成了全能紧密结合的哈密顿量，其参数拟合到Ab-Initio数据以较大角度拟合。然后，使用经受晶体和时间反转对称约束的最大关键化程序来构建低能对称的四波段和十二频段哈密顿量。最后，我们在约束的随机相位近似（CRPA）中计算两个模型的扩展哈伯德参数以进行筛选，这再次尊重对称性。这项工作的相关数据和结果可通过在线存储库免费获得。我们的工作流程在这项关于扭曲的双层石墨烯的工作中的例证，可以直接转移到其他扭曲的多层材料中。
A computationally efficient workflow for obtaining the low-energy symmetric tight-binding Hamiltonians for twisted multilayer systems is presented in this work. We apply this scheme to twisted bilayer graphene at the first magic angle. As initial step, the full-energy tight-binding Hamiltonian is generated by the Slater-Koster model with parameters fitted to ab-initio data at larger angles. Then, the low-energy symmetric four-band and twelve-band Hamiltonians are constructed using the maximum-localization procedure subjected to crystal and time-reversal-symmetry constraints. Finally, we compute extended Hubbard parameters for both models within the constrained random phase approximation (cRPA) for screening, which again respect the symmetries. The relevant data and results of this work are freely available via an online repository. Our workflow, exemplified in this work on twisted bilayer graphene, is straightforwardly transferable to other twisted multi-layer materials.
