论文标题
磁性二维（2D）CRX $ _3 $（x = i，br，br，cl，f）
Systematic DFT+U and Quantum Monte Carlo benchmark of magnetic two-dimensional (2D) CrX$_3$ (X = I, Br, Cl, F)
论文作者
论文摘要
由于实验性合成2D cri $ _3 $，对二维（2D）磁性材料的搜索引起了很大的关注，该合成具有45 k的测量库丽温度。通常，这些单层具有较高的电子相关性，并且需要更加成熟的方法超出密度功能理论（DFT）。扩散的蒙特卡洛（DMC）是一种相关的电子结构方法，它已被证明在计算各种2D和大量系统的电子和磁性方面已成功，因为它对Hubbard参数（U）和密度功能的依赖性较弱。在这项研究中，我们设计了一个将DFT+U和DMC结合在一起的工作流程，以治疗2D相关的磁系统。我们选择了单层CRX $ _3 $（x = i，br，cl，f），重点放在cri $ _3 $和crbr $ _3 $上，作为一个案例研究，因为它们已经实现了实验，并且具有有限的临界温度。使用此DFT+U和DMC工作流以及Torelli和Olsen的分析方法，我们估计CRI $ _3 $的T $ _c $ t $ _C $的上限为43.56 k，CRBR $ _3 $的T $ _C $ _C $ _C $ _C $ 20.78 k，此外还可以分析具有自旋密度和磁性属性和DMC和DMC和DMC和DMC和DMC+u。我们预计，为众所周知的材料类运行此工作流程将有助于未来的发现和表征鲜为人知且相关的2D磁性材料。
The search for two-dimensional (2D) magnetic materials has attracted a great deal of attention because of the experimental synthesis of 2D CrI$_3$, which has a measured Curie temperature of 45 K. Often times, these monolayers have a higher degree of electron correlation and require more sophisticated methods beyond density functional theory (DFT). Diffusion Monte Carlo (DMC) is a correlated electronic structure method that has been demonstrated successful for calculating the electronic and magnetic properties of a wide variety of 2D and bulk systems, since it has a weaker dependence on the Hubbard parameter (U) and density functional. In this study we designed a workflow that combines DFT+U and DMC in order to treat 2D correlated magnetic systems. We chose monolayer CrX$_3$ (X = I, Br, Cl, F), with a stronger focus on CrI$_3$ and CrBr$_3$, as a case study due to the fact that they have been experimentally realized and have a finite critical temperature. With this DFT+U and DMC workflow and the analytical method of Torelli and Olsen, we estimated an upper bound of 43.56 K for the T$_c$ of CrI$_3$ and 20.78 K for the T$_c$ of CrBr$_3$, in addition to analyzing the spin densities and magnetic properties with DMC and DFT+U. We expect that running this workflow for a well-known material class will aid in the future discovery and characterization of lesser known and more complex correlated 2D magnetic materials.
