Nanomechanical systems with small dissipation

Abstract

This thesis is devoted to a systematic development of methods for controlling energy dissipation in small mechanical systems, specifically nanomechanical resonators with at least one dimension in the deep nanometer range (< 200 nm). We explored three avenues for decreasing intrinsic dissipation and one method for decreasing non-contact friction. The three routes toward lower intrinsic dissipation are surface chemical engineering, alternative materials testing, and geometric optimization through nanofabrication. Reduction in non-contact friction between a vibrating nanomechanical resonator and a surface, spaced nanometers away from the latter, was achieved by using a diamond nanowire as an integrated scanning tip. Each of the four approaches led to between one and two orders of magnitude reduction in dissipation compared to the previous state-of-the-art in the literature. Planned integration of individual successful approaches is expected to result in devices with sufficient force sensitivity and with the suitable geometry for the nanomechanical detection of a single nuclear spin by magnetic resonance force microscopy.