Journal Article 2D magnets 2D materials 2D polar metal Coulomb blockade HfO2 angle‐resolved photoemission spectroscopy atomic layer deposition buckled honeycomb binary lattice density functional theory dirac nodal lines/points first‐principles calculations high-k dielectric monolayer magnet monolayer vanadium diselenide reconstructed line defects scanning probe microscopy spin frustration transition metal dichalcogenides van der Waals epitaxy vanadium diselenide