First principles investigation of screened Coulomb interaction and electronic structure of low- temperature phase TaS2

Abstract

By means of ab initio computation schemes, we examine the electronic screening, Coulomb interaction strength, and the electronic structure of a quantum spin liquid candidate monolayer TaS2 in its low-temperature commensurate charge -density-wave phase. Not only local (U) but non-local (V ) correlations are esti-mated within random phase approximation based on two different screening models. Using GW + EDMFT (GW plus extended dynamical mean-field theory) method, we investigate the detailed electronic structure by increasing the level of non-local approximation from DMFT (V = 0) to EDMFT and GW + EDMFT.