Microwave excitation and readout of nano- and micron scale cantilevers

Abstract

We show that a microwave near-field coaxial resonator system allows mechanical cantilever excitation on a scale much shorter than the microwave wavelength. Thermal noise is observed in the unexcited system, enabling room temperature displacement sensitivity of ∼70fm/Hz1/2. The measured force between near-field probe and cantilever varies with separation, in excellent agreement with theory. Uniquely, optical excitation and read-out lasers are also included. The dependence of mechanical resonator quality factor on ambient air pressure has been accurately measured. We have demonstrate passive cantilever mode cooling from 300K to 80K by frequency detuning the microwave resonator and propose pulsed cooling operation to enable several high-sensitivity applications.