Temperature and Thermal Noise Suppression for Precision Mechanical Experiments

Abstract

There is currently a lack of experiments that would prove whether gravity exists as a quantum field. One possible proof of the quantum nature of gravity would be to entangle massive quantum harmonic oscillators. This quantum harmonic oscillator acts as a resonant sensor for the entanglement with gravity. The quality factor of a resonant sensor must be sufficiently high such that the sensor is not dominated by thermal noise and the sensor can be cooled to the ground state. This thesis creates scaling laws for the interaction between the mass size bonded to a membrane resonator and the resonator's quality factor. With such a resonator, the entanglement is anticipated to be weak and requires extensive averaging to achieve statistically significant measurements. As such, the creation of a long time stable environment is critical. Thus, the lab temperature where the experiment will be run was stabilized to an integrated deviation of 20mK from 1K. This resulted in a reduction of laser position noise by a factor of 2.7x.