"Effective Quantum Field Theory and Graphene"

Abstract
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This is an pedagogical introduction into an "Effective QFT"- description
of graphene. The lecture explains the "pseudospin" (sublattice) and "valley" (Dirac
point) degrees of freedom of electrons of the graphene lattice. Then, using a
tight-binding model, the effective Dirac Hamiltonian of
quasirelativistic massless electrons is derived. On this basis, the so-called Klein
paradox and the chiral symmetry breaking of the U(2) valley-sublattice symmetry are
discussed. Finally, a pseudopotential model
for defects in graphene is presented and its relation to defect-induced gauge fields
is discussed.