Study of the coherent states of the two-dimensional electron gas in graphene

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Study of the coherent states of the two-dimensional electron gas in graphene ****Graphene, an atomic layer of graphite, has become over the past years a star in material science and condensed matter physics. From a technological point of view, its strength, flexibility, transparency, high and controllable conductivity all provide a strong drive to explore its use for high-speed electronic circuits. For fundamental research, graphene is interesting because its electrons behave in a way which is radically different from that in a conventional two-dimensional electron gas (2DEG): they are massless and chiral with a relativistic dispersion relation and zero gap between valence and conduction bands. The objective of the proposed research is to study the optical and electrical transport properties of the 2DEG in graphene when Coulomb interaction between electrons is taken into account and when a strong perpendicular magnetic field is applied to the sample. At very low temperature and in samples with very low disorder, the combination of magnetic field and Coulomb interaction can lead to the formation of many-body states where electrons in the 2DEG behave collectively. Such states often have novel transport properties that may require new physical models for their understanding. They may also have optical or electronic properties that could lead to the fabrication of new microelectronic devices. We vary the parameters of the 2DEG in graphene to find the different many-body states and study their properties as the magnetic field, the electronic density, or the band structure of graphene is modified. A modification of the band structure occurs naturally in systems consisting of more than one layer of graphene such as bilayer and trilayer graphene.******************