Abstract
The quantum indeterminacy caused by non-commutativity of observables at different times sets a lower bound on the voltage noise power spectrum in any conducting material. This bound is calculated explicitly in the case of monolayer graphene. It is found that account of graphene pseudospin/valley band structure raises the quantum bound by a factor of 7/2 compared to the case of spinless charge carriers with a conical energy-momentum dispersion. The bound possesses all characteristic properties of 1/f noise, and its dependence on the charge carrier density is congruent to the experimentally observed.