Towards Measurement of the Standard Quantum Limit (Paperback)

This thesis is based on the study of a low-loss electrical and acoustical resonator, which has been developed for use as a novel transducer in attempted measurements of quantum mechanical effects in a macroscopic mass. The method of transductance is via the interaction between the electrical and mechanical resonances within a monolithic sapphire mono-crystal supported by a low-loss suspension system. Exploiting parametric back-action effects has allowed determination of the dependence of permittivity on strain in sapphire. This new technique yields results that are in agreement with existing reports assuming sapphire is isotropic. Further, this first-time measurement gives additional information showing that the dependence of permittivity on strain in sapphire is anisotropic. Although the sensitivity of the system is still orders of magnitude away from the quantum mechanical regime, this work serves as important foundations for further research.