  We study the effects of electrostatic gating on the magnetization
auto-oscillations induced by the local injection of electric current into a
ferromagnet/heavy metal bilayer. We find that the characteristic currents
required for the excitation, the intensity and the spectral characteristics of
the generated dynamical states can be tuned by the voltage applied to the
metallic gate separated from the bilayer by a thin insulating layer. We show
that the effect of electrostatic gating becomes enhanced in the strongly
nonlinear oscillation regime at sufficiently large driving currents. Analysis
shows that the observed effects are caused by a combination of electric
field-dependent surface anisotropy and electric field-dependent contribution to
the current-induced spin-orbit torques. The demonstrated ability to control the
microwave emission and spectral characteristics provides an efficient approach
to the development of electrically tunable microwave nano-oscillators.
