Yukawa force spectroscopy to search for violations of Newton’s law of gravity below 1 μm distances

Abstract

Gravity is well tested on several length scales, but some unified theories predict deviations in the region below 1 mm. In this thesis I will present a method to search for such deviations in the sub-micrometre length scale. Below 1 μm, the electrostatic and the Casimir force are stronger than the gravitational force by some magnitudes. To distinguish these forces, I have designed a new force measurement setup based on the frequency modulation AFM technique. Utilizing a quartz based parallelogram cantilever, it is feasible to measure these forces with sufficient accuracy for us to set new constraints for possible deviations of gravity. In this thesis I will present a new method of measuring such deviations of gravity, and show the initial results I have obtained using it. This will show that the measurement concept works, but that improvements are necessary before we can achieve optimum measurement uncertainty.