Dirac Fermions in Graphite
How realistic may be relativistic field models to describe phenomena occurring in a condensed matter system? Such a question should be particularly relevant for the systems with massless Dirac fermions. The first unambiguous experimental evidence for Dirac fermions occurrence in solids has been reported by I.Lukyanchuk and Y.Kopelevich for graphite in 2004, one year before the discovery of Dirac Fermions in graphite mono-layer (Graphene). The identification of Dirac fermions became possible due to phase-frequency analysis of quantum de Haas van Alphen and Shubnikov de Haas oscillations. Actually, this method allows the efficient phase definition in any quantum oscillation phenomena and can be considered as a new tool in the condensed matter research. The identification of two-dimensional Dirac fermions in graphite undoubtedly makes this system a natural solid-state laboratory to test predictions of relativistic theories of (2+1)-dimensional Dirac fermions.
Phase analysis of quantum oscillations in graphite,