论文标题
\ textit {ab intio}理论中的激子绝缘子的分配：nibr $ _2 $的情况
Assignment of excitonic insulators in \textit{ab initio} theories: the case of NiBr$_2$
论文作者
论文摘要
在这项工作中，我们对最先进的$ GW $+BSE方案内的Nibr $ _2 $的电子和光学性质进行了详细的第一原理分析，以确定该系统是否显示负激子能量，这将确定为（一半）激发量绝缘子。特别关注$ GW $频段结构的收敛性以及地面计算中使用的近似值与线性响应计算中使用的近似值之间的一致性。我们表明，这两个问题在识别Nibr $ _2 $的激发性质方面起着至关重要的作用。
In this work we perform a detailed first-principles analysis of the electronic and optical properties of NiBr$_2$ within the state-of-the-art $GW$+BSE scheme to determine whether this system displays negative excitonic energies, which would identify it as an (half) excitonic insulator. Particular attention is payed to the convergence of the $GW$ band structure and to the consistency between approximations employed in the ground-state calculations and approximations employed in the linear response calculations. We show that these two issues play a crucial role in identifying the excitonic nature of NiBr$_2$.
