Charge and magnetic ordering near inhomogeneities in monolayer 2H-NbSe2

Recent interest in two-dimensional dichalcogenide materials is compounded by an anisotropic spin-orbit coupling (SOC) and proximity to competing orders like charge density wave (CDW), spin density wave, and superconductivity. In monolayer 2H-NbSe2, the low-energy electronic structure is influenced by the presence of an Ising SOC, the formation of a 3Q CDW order (Q=2/3ΓM), and a nontrivial topology that includes the electronic environment near impurities and edges. Scanning tunneling microscopy (STM) experiments have observed a transition from a 3Q CDW order on the surface to a 1Q charge stripe order near its edges, and the presence of impurities leads to a nontrivial dependence of superconducting transition temperature on impurity concentration. First-principle calculations also predict that the material will have strong paramagnetic fluctuations and lie close to a magnetic instability. In this work, we use a realistic multiorbital model derived from density functional theory (DFT) calculations, and we implement it on a real-space Hamiltonian to study the interplay between Ising SOC, charge density wave, and a proximate magnetic order. We find that near inhomogeneities like impurities and edges, such an interplay can lead to interesting local charge and magnetic signatures that are in agreement with experimental observations such as 1Q CDW order near the material edge. We also find that due to an interplay with the underlying CDW state, the local electronic order near certain impurity sites in monolayer 2H-NbSe2 can show a twofold-symmetric pattern. Finally, we propose that strong spin fluctuations can lead to the formation of local magnetic order near disorder and influence the electronic properties of this material.