Electrothermal noise analysis in frequency tuning of nanoresonators

Electrothermal tuning mechanisms for nanoelectromechanical resonators are demonstrated. Voltages induced by oscillation of Al/SiC nanoresonators around 10 MHz in a moderate magnetic field are measured using a room-temperature tabletop setup in moderate vacuum. The dynamic range as well as the resonance frequency of the resonator can be reversibly controlled by electrothermal tuning using DC voltage. This paper presents experimental results that demonstrates the effect of the resonance frequency, Q factor and dynamic range during the electrothermal tuning process. As the input DC power increases, Q factor decreases due to the decrease in the resonance frequency, and SNR decreases due to the reduced amplitude and increased noise. This can be explained by thermal relaxation of the resonator structure during the tuning process, and Johnson noise and eddy current effects associated with the magnetomotive transduction.