Uniaxial magnetic anisotropy and weak phonon–spin coupling of a single Ni atom bonded to iridium-doped graphene

Abstract

We investigate the magnetism and vibrational mode of a single Ni atom bonded to iridium-doped graphene. It is found that the Ni atom exhibits a large magnetic anisotropy energy of 53 meV, and the magnetic anisotropy is perfectly uniaxial. There are no vibrational modes below 40 meV for the Ni atom, which disables the efficient coupling between the spin and phonon at the low magnetic field. The uniaxial magnetic anisotropy combining with the weak phonon–spin coupling effectively resists the quantum tunneling and spin flip, making the Ni atom a viable single atom magnet for information storage.