LAUSR

We study a new scheme to realize a quantized two-parameter charge pump based on massive Dirac electrons. It is shown that the two time-dependent and out-of-phase staggered potentials introduced in graphene can pump out an integer number of electrons in a pumping cycle as long as the Fermi energy resides in the effective energy gap opened by pumping potentials. The dependence of the pumped charge per mode on the pumping phase or the dynamic phase exhibits a binary alternation from $+e$ to $\ensuremath{-}e$. This quantization has a topological origin and can be accounted for by adiabatic evolution of the topologically protected interfacial state forming between the two pumping sources.