Curved graphene: a possible answer to the problem of graphene's diverging magnetic susceptibility

Abstract

A study of strongly curved graphene magnetization and magnetic susceptibility is carried out. Through a Dirac model complemented with a tight-binding model analysis, we are able to show that mechanical deformations solve the long-standing problem of graphene's theoretically calculated diamagnetic divergence at low temperatures. This suggests that corrugations and mechanical defects in graphene are the cause of finite experimentally measurable magnetic susceptibility. Furthermore, a mechanical effect is also found due to an electronic contribution, which produces a pseudo-de Haas van Alphen (dHvA) effect. This effect is related to oscillating (electronic) forces that oppose deformations; these forces are divergent in flat graphene, indicating that graphene (without substrate) achieves mechanical equilibrium by corrugations. In addition, paramagnetism is predicted for graphene with negative curvature under strong magnetic fields.