Zigzag edge ferromagnetism of triangular-graphene-quantum-dot-like system

Abstract

The magnetic susceptibility of a triangular-graphene-quantum-dot-like system was examined by using the determinant quantum Monte Carlo method. We focused on three kinds of zigzag edge quantum dots or rings, namely the triangular graphene quantum ring, twist bilayer triangular graphene quantum dot, and twist bilayer triangular graphene quantum ring. The triangular-graphene-quantum-dot-like system exhibits robust edge ferromagnetic behavior, which is independent of size, monolayer or bilayer, and dot or ring shape, according to the unbiased numerical results. At half filling, the edge magnetic susceptibility is increased by on-site interaction, especially in low temperature region. Applications of this system in spintronics may benefit from the robust edge ferromagnetic behavior.Comment: 6 pages, 7 figure