Controllability of ferromagnetism in graphene

TL;DR

This study uses quantum Monte Carlo simulations to explore how ferromagnetism in graphene can be controlled via electronic filling and interactions, highlighting potential for tunable magnetic properties in graphene-based devices.

Contribution

It provides a systematic analysis of ferromagnetic correlations in graphene within the Hubbard model, emphasizing controllability through electron filling and hopping parameters.

Findings

Ferromagnetic correlations are enhanced by next-nearest-neighbor hopping.

Ferromagnetism is strongly dependent on electron filling, tunable by electric gating.

Graphene's ferromagnetic properties can be manipulated for applications.

Abstract

We systematically study magnetic correlations in graphene within Hubbard model on a honeycomb lattice by using quantum Monte Carlo simulations. In the filling region below the Van Hove singularity, the system shows a short-range ferromagnetic correlation, which is slightly strengthened by the on-site Coulomb interaction and markedly by the next-nearest-neighbor hopping integral. The ferromagnetic properties depend on the electron filling strongly, which may be manipulated by the electric gate. Due to its resultant controllability of ferromagnetism, graphene-based samples may facilitate the development of many applications.