Tuning mechanical modes and influence of charge screening in nanowire resonators

Abstract

We probe electromechanical properties of InAs nanowire (diameter $\ensuremath{\sim}100\text{ }\text{nm}$) resonators where the suspended nanowire is also the active channel of a field-effect transistor. We observe and explain the nonmonotonic dispersion of the resonant frequency with dc gate voltage $({V}_{g}^{\text{dc}})$. The effect of electronic screening on the properties of the resonator can be seen in the amplitude. We observe the mixing of mechanical modes with ${V}_{g}^{\text{dc}}$. We also experimentally probe and quantitatively explain the hysteretic nonlinear properties, as a function of ${V}_{g}^{\text{dc}}$, of the resonator using the Duffing equation.