Quantum interference and domain-wall-like magnetic correlations in hexagonal graphene nanodisks.

Quantum interference and traditional domain wall effects are two common ways to manipulate the magnetism in magnetic materials. Here, we report both effects emerge in the designed graphene nanodisks simultaneously, and thus providing an accessible way to engineer the magnetism in graphene nanostructures. By adjusting the length of the armchair edges at the corners of hexagonal disk, connecting the adjacent zigzag edges, we show that the quantum interference among the zigzag edges remains robust and consequently determines the magnetic structure in the small-size systems, in analogy with the nanoribbons. More importantly, a domain-wall-like magnetic mechanism is numerically identified to dominate the larger-size disks. In particular, a magnetic state with fully spin-polarized edges achieved in a wide parameter region promises the future applications for spintronics.