Effects of the spin–orbit coupling on the vacancy-induced magnetism on the honeycomb lattice

Abstract

The local magnetism induced by vacancies in the presence of the spin-orbital interaction is investigated based on the half-filled Kane-Mele-Hubbard model on the honeycomb lattice. Using the self-consistent mean-field theory, we find that the spin-orbital coupling will enhance the localization of the spin moments near a single vacancy. We further study the magnetic structures along the zigzag edges formed by a chain of vacancies. We find that the spin-orbital coupling tends to suppress the counter-polarized ferrimagnetic order on the upper and lower edges, because of the open of the spin-orbital gap. As a result, in the case of the balance number of sublattices, it will suppress completely this kind of ferrimagnetic order. But, for the imbalance case, a ferrimagnetic order along both edges exists because additional zero modes will not be affected by the spin-orbital coupling.

Impurity-induced magnetic moments on the graphene-lattice Hubbard model: An inhomogeneous cluster dynamical mean-field theory study

“…There is a local antiferromagnetic moment around the impurity site. The resulting antiferromagnetic pattern has been observed in other theoretical studies of the vacancy defect in graphene using mean-field 9,46 or density functional theory. 10 The 120 • rotation symmetry is not exactly found in our solution since both the cluster and the supercluster do not have that symmetry.…”

Phase diagram of graphene in the presence of spin-orbit coupling and electron-electron interaction

“…The SOC also contributes to suppress the edge magnetism in the zigzag graphene nanoribbon [21]. Leong et al, [22] revealed the enhancement of localized spin moments near a single vacancy under affecting the SOC. The change of topological edge states and spontaneous magnetic moment properties of zigzag graphene nanoribbons were reported recently [23].…”

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

“…Alternatively, the strong correlation effects may be introduced by suppression the itinerancy of p z electrons. Following this idea, several schemes to trigger the magnetism in graphene nanostructures were proposed by breaking the perfect sp 2 network and generating the local imbalance of bipartite sublattice of graphene [7], including the atomic vacancies [8][9][10], adsorbing adatoms [11], sp 3 functionalization [12], substitutional doping [13][14][15], and the zigzag edges in the nanoflakes such as the nanoribbons or nanoislands [16][17][18]. For example, the atomic vacancies and chemisorbed hydrogen atom on graphene can induce the unusually several-nanometers-distant spin texture [11], the sulfur-and nitrogen-doped graphene can produce the strong room-temperature ferromagnetism [19][20][21][22], and the zigzag edges can generate the strong ferromagnetism along the edges due to the flat band emerging at the edges [23][24][25].…”