Role of non-locality in exchange-correlation for magnetic 2D van der Waals materials

Abstract

To obtain accurate independent-particle descriptions for ferromagnetic two-dimensional van der Waals materials, we apply the quasiparticle self-consistent $GW$ (QSGW) method to VI${}_3$, CrI${}_3$, CrGeTe${}_3$, and Fe${}_3$GeTe${}_2$. QSGW provides a description of the nonlocal exchange-correlation term in the one-particle Hamiltonian. The nonlocal term is important not only as the $U$ of density functional theory (DFT)+$U$ but also for differentiating occupied and unoccupied states in semiconductors. We show the limitations of DFT+$U$ in mimicking QSGW.

6 pages, 6 figures, Supplemental Material