论文标题
在分层的NBSE $ _ {2} $中的磁性和电荷不稳定性之间的相互作用
Interplay between magnetism and charge instabilities in layered NbSe$_{2}$
论文作者
论文摘要
使用基于密度函数理论的AB ITIOL方法，研究了分层NBSE $ _ {2} $的电子和磁结构。在单层NBSE $ _ {2} $的情况下，发现，对于所有考虑的功能，磁溶液的能量均低于非磁性解决方案。磁基态是铁磁性的，在NB原子处的磁矩为1.09 $μ_{B} $，在相反的方向上，在SE原子上的磁矩为0.05 $μ_{B} $。我们的计算表明，除非将石墨烯层视为底物，否则单层NBSE $ _ {2} $不显示电荷密度波不稳定性。然后，发现了两种3 $ \ times $ 3的电荷密度波，这在我们的STM实验中观察到。这表明NBSE $ _ {2} $中电荷不稳定性的驱动力在批量和单层限制方面有所不同。我们的工作使磁性在这种高度相关的2D材料中发挥作用，这对于了解2D超导性和电荷密度波顺序的形成机理至关重要。
Using ab initio methods based on density functional theory, the electronic and magnetic structure of layered hexagonal NbSe$_{2}$ is studied. In the case of single-layer NbSe$_{2}$ it is found that, for all the functionals considered, the magnetic solution is lower in energy than the non-magnetic solution. The magnetic ground-state is ferrimagnetic with a magnetic moment of 1.09 $μ_{B}$ at the Nb atoms and a magnetic moment of 0.05 $μ_{B}$, in the opposite direction, at the Se atoms. Our calculations show that single-layer NbSe$_{2}$ does not display a charge density wave instability unless a graphene layer is considered as a substrate. Then, two kinds of 3$\times$3 charge density waves are found, which are observed in our STM experiments. This suggest that the driving force of charge instabilities in NbSe$_{2}$ differ in bulk and in the single-layer limit. Our work sets magnetism into play in this highly-correlated 2D material, which is crucial to understand the formation mechanisms of 2D superconductivity and charge density wave order.
