Schematic of the sample (left) and the pumping protocol
on the energy scale (right)
  Pump voltage dependence of the coherent oscillations

Coherent Phonon Manipulation in Coupled Mechanical Resonators

   We realized the coherent manipulation of coupled GaAs mechanical beams by the parametric pumping. The piezoelectric modulation of the spring constant of one beam at the frequency difference between the two beams via the gate voltage leads to the cyclic (Rabi) oscillations of phonons between the beams. The oscillation period is inversely proportional to the pump amplitude, enabling the time-domain control of the mechanical vibration via the gate control. (Page 31)