Dynamic gauge field and quantum pumping in graphene nanoelectromechanical resonators

Quantum pumping generates charge or valley current through periodic variation in its internal parameters. Graphene, with its large electron mobility and strong coupling between electronic properties and mechanical strain, is a promising candidate for the experimental realization of quantum pumping. Here we study the case of graphene nanoelectromechanical resonator suspended over a gate electrode as a quantum charge pump. The deformation of graphene sheet from electrostatic potential induces a cyclic modulation of carrier density as well as an effective dynamic gauge potential. By explicit breaking of spatial inversion symmetry, we observed a finite charge pumping current near the mechanical resonance frequency. We also explore the possibility of generating valley current in graphene nanoelectromechanical resonators.