Coulomb interaction in graphene

Aperture partiallycovered by grapheneOptical transparency of graphene• Recent Experiments: Graphene nearly transparentNair et al, Science 2008: “Fine structure constant defines visual transparencyof graphene”See also Kuzmenko et alPRL 2008 -- graphiteTransmittance: t = 97.7%1Measures conductivity in• Theory*: t(") =(1+ 2#$(") /c) 2 optical regime!!*Stauber et al PRB 2008Next: Are interactions important?!