Ground-state magnetic phase diagram of bow-tie graphene nanoflakes in external magnetic field
arXiv:1312.7298 · doi:10.1063/1.4858378
Abstract
The magnetic phase diagram of a ground state is studied theoretically for graphene nanoflakes of bow-tie shape and various size in external in-plane magnetic field. The tight-binding Hamiltonian supplemented with Hubbard term is used to model the electronic structure of the systems in question. The existence of the antiferromagnetic phase with magnetic moments localized at the sides of the bow-tie is found for low field and a field-induced spin-flip transition to ferromagnetic state is predicted to occur in charge-undoped structures. For small nanoflake doped with a single charge carrier the low-field phase is ferrimagnetic and a metamagnetic transition to ferromagnetic ordering can be forced by the field. The critical field is found to decrease with increasing size of the nanoflake. The influence of diagonal and off-diagonal disorder on the mentioned magnetic properties is studied. The effect of off-diagonal disorder is found to be more important than this of diagonal disorder, leading to significantly widened distribution of critical fields for disordered population of nanoflakes.
References in corpus (15)
- Electric Field Effect in Atomically Thin Carbon Films
- Valley filter and valley valve in graphene
- A tight-binding approach to uniaxial strain in graphene
- Emergence of magnetism in graphene materials and nanostructures
- Magnetism in graphene nano-islands
- Metallic Graphene Nanodisks
- Strained graphene: tight-binding and density functional calculations
- Spintronics with graphene
- Orbital magnetism of graphene flakes
- Spin Filter, Spin Amplifier and Other Spintronic Applications in Graphene Nanodisks
- Confined states in quantum dots defined within finite flakes of bilayer graphene: Coupling to the edge, ionization threshold, and valley degeneracy
- Quasi-Ferromagnet Spintronics in Graphene Nanodisk-Lead System
- Indirect coupling between localized magnetic moments in triangular graphene nanoflakes
- Generation and Manipulation of Spin Current in Graphene Nanodisks: Robustness against Randomness and Lattice Defects
- Indirect coupling between localized magnetic moments in zero-dimensional graphene nanostructures (quantum dots)