Origin of the quasiuniversality of the minimal conductivity of graphene
Origin of the quasiuniversality of the minimal conductivity of graphene
It is a fact that the minimal conductivity ${\ensuremath{\sigma}}_{0}$ of most graphene samples is larger than the well-established universal value for ideal graphene $4{e}^{2}/\ensuremath{\pi}h$; in particular, larger by a factor $\ensuremath{\gtrsim}\ensuremath{\pi}$. Despite intense theoretical activity, this fundamental issue has eluded an explanation so far. Here we present fully atomistic quantum …