Che J G
Surface Physics Laboratory (National Key Laboratory), Key Laboratory of Computational Physical Sciences (MOE), Department of Physics and Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai 200433, People's Republic of China.
J Phys Condens Matter. 2020 May 8;32(19):195802. doi: 10.1088/1361-648X/ab6e42.
To elucidate the physics associated with the magnetism observed in nominally nonmagnetic materials containing only sp-electrons, we have developed an extreme model to simulate the adsorption of H (in a straight-line form) on graphene. Our first principles calculations for the model result in a ferromagnetic ground state at a high temperature with a magnetic moment of one Bohr magneton per H atom. The removal of p -orbitals from sublattice B of graphene introduces p -vacancies. The p -vacancy-induced states are created not because of the variations in interatomic interactions but because of the p -orbital imbalance between two sublattices (A and B) of the conjugated p -orbital network. Therefore, some critical requirements should be satisfied to create these states (denoted as [Formula: see text]) to avoid further imbalances and to minimally affect the conjugated p -orbital network. The requirements for the creation of [Formula: see text] can be given as follows: (1) [Formula: see text] consists of p -orbitals of only the atoms in sublattice A, (2) the spatial wavefunction of [Formula: see text] is antisymmetric, and (3) in principle, [Formula: see text] extends over the entire crystal without decaying, unless other p -vacancies are encountered. Both the origin of spin polarization and the magnetic ordering of the model can be attributed to the aforementioned requirements.
