论文标题
k $ _2 $ cos $ _2 $：新的二维平面抗铁磁绝缘子
K$_2$CoS$_2$: A new two-dimensional in-plane antiferromagnetic insulator
论文作者
论文摘要
最近发现的二维（2D）磁性材料使磁力震撼了平坦。这为探索基本物理以及新型设备应用打开了令人兴奋的机会。在这里，我们预测一种新的热力学稳定的2D磁性材料，K $ _2 $ cos $ _2 $，该材料将其平面抗铁磁性订单保留到单层和双层限制。我们发现，从单层到散装的磁矩（$2.5μ_b/$ co）沿着内部链条对齐。发现单层和双层薄膜的非磁电子光谱均可容纳平坦的频带和货车霍夫奇异性，这在产生磁场状态方面发挥了作用。基于经典的蒙特卡洛模拟，我们估计抗磁性单层的Neel温度约为$ \ 15 $ k。因此，我们的研究表明，k $ _2 $ cos $ _2 $托管一个坚固的抗铁磁状态，从单层限制到批量材料。
The recent discovery of two-dimensional (2D) magnetic materials has brought magnetism to the flatland. This has opened up exciting opportunities for the exploration of fundamental physics as well as for novel device applications. Here, we predict a new thermodynamically stable 2D magnetic material, K$_2$CoS$_2$, which retains its in-plane anti-ferromagnetic order down to the monolayer and bilayer limits. We find that the magnetic moments ($2.5 μ_B/$Co) are aligned along the intra-Co chains, from monolayer to bulk. The non-magnetic electronic spectrum of both the monolayer and bilayer films is found to host flat bands and van-Hove singularities, which in instrumental in giving rise to the the magnetic ground state. Based on classical Monte-Carlo simulations, we estimate the Neel temperature for the antiferromagnetic monolayer to be $\approx 15$K. Our study thus establishes that K$_2$CoS$_2$ hosts a robust antiferromagnetic state which persists from the monolayer limit to the bulk material.
