Design, methodologies, and characterization of magneto-gravitational traps for use in measuring Newtonian gravitational constant G

Abstract

There is poor consensus to date on the accepted value of the Newtonian constant of gravitation G, despite multiple recent studies attempting high-precision measurements of the parameter. In this work we discuss the design of a levitated optomechanical system, constructed using a magneto-gravitational trap under ultra-high vacuum with a graphite composite test mass, as a system for performing such a measurement. Through tilt- stabilization, the use of a single point diamond turning machine, and careful control of the trapping potential, an oscillator with a frequency of about 0.28 Hz with a damping rate insignificant to other noise sources in the system has been constructed. Additionally, work on this system resulted in the development of a selective loading technique with potential application in a multitude of levitated optomechanical systems and a possible measurement scheme for building a spin-mechanical coupled system using V- Si (V2) vacancy defect centers in levitated silicon carbide. The results are a significant step towards the construction of a high-precision levitated optomechanical system for measuring G.