  The extremely high pseudo-magnetic field emerging in strained graphene
suggests that an oscillating nano-deformation will induce a very high current
even without electric bias. In this paper, we demonstrate the sub-terahertz
(THz) dynamics of a valley-current and the corresponding charge pumping with a
periodically excited nano-bubble. We discuss the amplitude of the
pseudo-electric field and investigate the dependence of the pumped valley
current on the different parameters of the system. Finally, we report the
signature of extra-harmonics generation in the valley current that might lead
to potential modern devices development operating in the nonlinear regime
