We report the first isoelectronic differential force measurements between an Au-coated probe and two Au-coated films, made out of Au and Ge. These measurements, performed at submicron separations using soft microelectromechanical torsional oscillators, eliminate the need for a detailed understanding of the probe-film Casimir interaction. The observed differential signal is directly converted into limits on the parameters α and λ which characterize Yukawa-like deviations from Newtonian gravity. We find α 1012 for λ∼200nm, an improvement of ∼10 over previous limits.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)