Optomechanical vector sensing of new forces at 6 micron separation

Abstract

Abstract The search for new gravity-like interactions at the sub-millimeter scale is a compelling area of research, with important implications for the understanding of classical gravity and its connections with quantum physics. We report improved constraints on Yukawa-type interactions in the $$10\,\mathrm {\mu m}$$ regime using optically levitated dielectric microspheres as test masses. The search is performed, for the first time, sensing multiple spatial components of the force vector, and with sensitivity improved by a factor of $$\sim 100$$ with respect to previous measurements using the same technique. The resulting upper limit on the strength of a hypothetical new force is $$10^7$$ at a Yukawa range $$\lambda \simeq 5\;\mu$$ m and close to $$10^6$$ for $$\lambda \gtrsim 10\;\mu$$ m. This result also advances our efforts to measure gravitational effects using micrometer-size objects, with important implications for embryonic ideas to investigate the quantum nature of gravity.