Orbital selective Mott transition and magnetic moment in charge density wave heterostructures NbSe$_2/$Ta$X_2$

Joydeep Chatterjee; Shubham Patel; A Taraphder

paper

Orbital selective Mott transition and magnetic moment in charge density wave heterostructures NbSe $_{2} /$ Ta $X_{2}$

arXiv:2410.00600

Abstract

We investigate the electronic properties of charge density wave (CDW) heterostructures out of monolayers of 1T-NbSe $_{2}$ and 1T-Ta $X_{2}$ (where, $X =$ S and Se) using first-principles followed by dynamical calculations. The CDW-ordered crystal structures are simulated using $13 \times 13$ supercells of NbSe $_{2}$ and Ta $X_{2}$ . These two-dimensional heterostructures are modeled by stacking monolayers of NbSe $_{2}$ and Ta $X_{2}$ along (001) direction. Our investigations reveal the presence of non-zero magnetic moments in NbSe $_{2} /$ TaS $_{2}$ , albeit without a long-range magnetic order, raising the issue of a possible quantum spin liquid (QSL) as suggested for monolayer 1T-TaS $_{2}$ recently. In contrast, the NbSe $_{2} /$ TaSe $_{2}$ heterostructure exhibits no magnetic moment. In order to capture the dynamical effects of local correlation, we use DFT plus multi-orbital dynamical mean field theory (MO-DMFT). Our findings indicate that NbSe $_{2} /$ TaS $_{2}$ is considerably influenced by the dynamic corrections, whereas NbSe $_{2} /$ TaSe $_{2}$ shows minimal effects. Additionally, an orbital-selective Mott transition (OSMT) is observed in the NbSe $_{2} /$ TaS $_{2}$ bilayer heterostructure.

arXiv comment8 pages including references, 4 figures, JC and SP contributed equally

Orbital selective Mott transition and magnetic moment in charge density wave heterostructures NbSe2​/TaX2​

Abstract

Orbital selective Mott transition and magnetic moment in charge density wave heterostructures NbSe $_{2} /$ Ta $X_{2}$