Pristine graphene, a two-dimensional honeycomb carbon lattice is a zero gap semiconductor. Thesp2 hybridized carbon atoms are arranged in hexagonal fashion in 2-dimensional layer. A single hexagonal ring comprises of three strong in-plane sigma bonds Pz orbitals perpendicular to the planes.Different graphene layers are bonded by weak pz interaction while strong in-plane bonds keep hexagonal structure stable and facilitate de-lamination of 3D structure (graphite) into individual graphenesheet just by applying mechanical stress. As described earlier, the scotch tape method micromechanically creates single layer of defect free graphene and provides a 2-D platform, to investigate manyfundamental properties of this 2-D crystal.One of the most interesting aspects of the graphene is its highly unusual nature of charge carriers,which behave as massless relativistic particles (Dirac fermions). Dirac fermions behavior is veryabnormal compared to electrons when subjected to magnetic fields for example, the anomalous integer quantum Hall effect (QHE) [2,161]. This effect was even observed at room temperature [3]. Graphene has distinctive nature of its charge carriers, which mimic relativistic particles, considered aselectrons those have lost their rest mass, can be better described with (2 + 1) dimensional Dirac equation [162]. The band structure of single layer graphene exhibits two bands intersecting at two in
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