ORBITAL MAGNETISM OF DIRAC FERMIONS – DIRACFORMAG

Electronic properties of graphene have attracted a lot of interest due to its electronic Dirac-particle like spectrum leading to spectacular signatures in transport properties. In contrast, orbital magnetism has not yet been explored experimentally, in spite of a number of recent theoretical predictions demonstrating that this thermodynamic quantity can reveal original aspects of the electronic properties unaccessible from transport measurements. It was found that despite a vanishing density of states, graphene has a very strong orbital diamagnetism right at half filling which sign and singular behaviour are strongly related to the topological properties and Berry phase of the electronic wave functions. However this orbital magnetism and its dependence on the Fermi energy has not yet been measured due to experimental difficulties. The aim of this project is to experimentally and theoretically explore the fundamental properties of orbital magnetism in graphene and related materials containing Dirac fermions. Besides band structure and Berry phase effects, phase coherence and interactions effects will be investigated.