Enhancing non-Newtonian gravity constraint using a levitated pendulum in vacuum

Abstract

The detection of non-Newtonian gravity is crucial for fundamental physics research and our understanding of dark energy. However, conducting an experiment that provides explicit evidence of its existence remains an endeavour. We propose an experiment utilizing a diamagnetically levitated pendulum in vacuum to detect non-Newtonian gravity on a micrometer scale. The pendulum configuration effectively helps to shield electromagnetic force fluctuations in the vacuum levitation system. The structural parameters of the pendulum are intentionally optimized to enhance the constraint on the non-Newtonian gravity strength $\alpha$. The designed pendulum can be stably levitated in the diamagnetic trap thanks to its passive levitation mechanism. By conducting resonance force measurements at room temperature for a duration of ${10}^4$ s, we anticipate a significant improvement in the constraint on the non-Newtonian gravity strength ($\alpha \ge 28$) within the force range of $\lambda =7.6$ µm. This represents an enhancement of over three orders of magnitude compared to the current limit. This study presents a promising tool for investigating short-range forces and exploring frontier physics in tabletop laboratory.