论文标题
单层和块状六角硼的电子特性的扩散量子蒙特卡洛和GW研究
Diffusion quantum Monte Carlo and GW study of the electronic properties of monolayer and bulk hexagonal boron nitride
论文作者
论文摘要
我们报告了单层和散装六角硼硝化硼（HBN）的电子带隙的扩散量子蒙特卡洛（DMC）和多体$ GW $计算。我们发现单层带隙是间接的。 $ gw $预测单一$ g_0w_0 $和部分自洽的$ gw_0 $ lacte的$ g_0w_0 $的较小的准粒子差距。相比之下，在$ GW_0 $计算之上求解Bethe-Salpeter方程会产生与DMC值密切一致的$ K $点的直接激子的激子结合能。发现电子带隙的振动重新归一化在单层和整体中都很重要。考虑到振动效应，DMC高估了散装HBN的频段隙，而$ GW $理论则低估了它。
We report diffusion quantum Monte Carlo (DMC) and many-body $GW$ calculations of the electronic band gaps of monolayer and bulk hexagonal boron nitride (hBN). We find the monolayer band gap to be indirect. $GW$ predicts much smaller quasiparticle gaps at both the single-shot $G_0W_0$ and the partially self-consistent $GW_0$ levels. In contrast, solving the Bethe-Salpeter equation on top of the $GW_0$ calculation yields an exciton binding energy for the direct exciton at the $K$ point in close agreement with the DMC value. Vibrational renormalization of the electronic band gap is found to be significant in both the monolayer and the bulk. Taking vibrational effects into account, DMC overestimates the band gap of bulk hBN, while $GW$ theory underestimates it.
