Comparison of GW band structure to semiempirical approach for an FeSe monolayer
Comparison of GW band structure to semiempirical approach for an FeSe monolayer
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DOI：
10.1103/physrevb.101.235154
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发表时间：
2020-06
影响因子：
3.7
通讯作者：
D. Qiu;Sinisa Coh;M. Cohen;S. Louie
中科院分区：
文献类型：
--
作者：
D. Qiu;Sinisa Coh;M. Cohen;S. Louie
基于Kohn Sham密度泛函理论(DFT)和PBE泛函的起始平均场，给出了顺磁相单分子层FeSe的能带结构、芯能级和形变势能.我们发现GW修正增加了费米能量附近形成$M$口袋的态的带宽，而$\Gamma$口袋大致保持不变。然后，我们将G$0$W$0$准粒子能带能带结构与最近提出的一种简单的经验+A方法进行了比较，该方法用来捕捉FeSe中电子-声子相互作用超出密度泛函微扰理论(DFPT)的重整化。结果表明，这种经验修正成功地近似了单层FeSe中的GW非局域和动态自能，并再现了费米面附近的GW能带结构、核心能级和形变势能(电子-声子耦合)。
We present the G$_0$W$_0$ band structure, core levels, and deformation potential of monolayer FeSe in the paramagnetic phase based on a starting mean field of the Kohn Sham density functional theory (DFT) with the PBE functional. We find the GW correction increases the bandwidth of the states forming the $M$ pocket near the Fermi energy, while leaving the $\Gamma$ pocket roughly unchanged. We then compare the G$_0$W$_0$ quasiparticle band energies with the band structure from a simple empirical +A approach, which was recently proposed to capture the renormalization of the electron-phonon interaction going beyond DFT in FeSe, when used as a starting point in density functional perturbation theory (DFPT). We show that this empirical correction succeeds in approximating the GW non-local and dynamical self energy in monolayer FeSe and reproduces the GW band structure near the Fermi surface, the core energy levels, and the deformation potential (electron-phonon coupling).