论文标题
二维Van der Waals NB $ _3 $ x $ _8 $单层（x = Cl，Br，and i）
Mottness in two-dimensional van der Waals Nb$_3$X$_8$ monolayers (X=Cl, Br, and I)
论文作者
论文摘要
我们研究了对二维Van der Waals材料NB $ _3 $ x $ _8 $（X = Cl，Br，I）对强型电子电子相关效应。我们发现单层NB $ _3 $ x $ _8 $是接近强相关限制的理想系统。它们可以通过半填充的单个带哈伯德模型来描述，其中哈伯德，u和带宽，w，u/w $ \ $ 5 $ \ sim $ 10 $ 10。掺杂Mott State，找到了$ d_ {x^2-y^2}+id_ {xy} $超导配对不稳定性。我们还为两个滑动nb $ _3 $ x $ _8 $ layers构建了一个可调双层哈伯德系统。双层系统显示带绝缘子和Mott绝缘子之间的交叉。
We investigate strong electron-electron correlation effects on 2-dimensional van der Waals materials Nb$_3$X$_8$ (X=Cl, Br, I). We find that the monolayers Nb$_3$X$_8$ are ideal systems close to the strong correlation limit. They can be described by a half-filled single band Hubbard model in which the ratio between the Hubbard, U, and the bandwidth, W, U/W $\approx$ 5 $\sim$ 10. Both Mott and magnetic transitions of the material are calculated by the slave boson mean field theory. Doping the Mott state, a $d_{x^2-y^2}+id_{xy}$ superconducting pairing instability is found. We also construct a tunable bilayer Hubbard system for two sliding Nb$_3$X$_8$ layers. The bilayer system displays a crossover between the band insulator and Mott insulator.
