Electron-electron interactions in the conductivity of graphene

The effect of electron-electron interaction on the low-temperature conductivity of graphene is investigated experimentally. Unlike in other two-dimensional systems, the electron-electron interaction correction in graphene is sensitive to the details of disorder. A temperature regime of the interaction correction is identified where quantum interference is partially suppressed by intravalley scattering. We determine the value of the interaction parameter, F-0(sigma) similar or equal to -0.1, and show that its small value is due to the chiral nature of interacting electrons.