Excitation, detection, and passive cooling of a micromechanical cantilever using near-field of a microwave resonator

Micro/nanomechanical resonators are important for nanoscale and quantum physics. 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 similar to 70 fm/Hz(1/2). 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. We demonstrate passive cantilever mode cooling from 300 to 100 K by frequency detuning the microwave resonator and propose pulsed cooling operation to enable several high-sensitivity applications. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3224912]