We undertook a comprehensive investigation of the electronic structure of FeSe, known as a Hund metal, and found that it is not uniquely defined. Through accounting for all two-particle irreducible diagrams constructed from electron Green’s function $G$ and screened Coulomb interaction $W$ in a self-consistent manner, a Mott-insulator phase of 2D-FeSe is unveiled. The metal-insulator transition is driven by the strong on-site Coulomb interaction in its paramagnetic phase, accompanied by the weakening of both local and nonlocal screening effects on the Fe-$3d$ orbitals. Our results suggest that Mott physics may play a pivotal role in shaping the electronic, optical, and superconducting properties of monolayer or nanostructured FeSe.

中文翻译：

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作为范德华二维材料的 FeSe 莫特绝缘体态已揭晓


我们对 FeSe（一种洪德金属）的电子结构进行了全面的研究，发现它没有唯一的定义。通过以自洽的方式解释由电子格林函数 $G$ 和屏蔽库仑相互作用 $W$ 构建的所有双粒子不可约图，揭示了 2D-FeSe 的莫特绝缘体相。金属-绝缘体转变是由其顺磁相中强烈的现场库仑相互作用驱动的，伴随着Fe- $3d$ 轨道上局域和非局域屏蔽效应的减弱。我们的结果表明，莫特物理学可能在塑造单层或纳米结构 FeSe 的电子、光学和超导特性方面发挥关键作用。