Towards Gravity Tests at Sub-Micron Scale With Levitated Nanoparticles*

Nano- and micron-sized dielectric objects trapped with optical tweezers in a cryogenic extremely-high-vacuum (CEHV) environment open doors to new precision tests of the standard model [1]. Thanks to decoupling by levitation, low environmental noise combined with active center-of-mass laser cooling [2] quantum shot-noise limited force measurements are in reach. Of particular interest is the search for deviations from the inverse-square-law of gravity [3]. 

I will report on our optical trap in a new CEHV vibration-stabilized vacuum chamber, combined with a lithographically fabricated source mass for gravity measurements at a sub-micron scale. The progress of the experiment, together with expected statistical and systematic uncertainties using simulations and current experimental data, will be presented. 

[1] D. C. Moore and A. A. Geraci, (2021),  Searching for new physics using optically levitated sensors. Quantum Sci. Tecnol. 6.

[2] L. Magrini, P. Rosenzweig, C. Bach, A. Deutschmann-Olek, S. Hofer, S. Hong, N. Kiesel, A. Kugi and M. Aspelmeyer, (2021),  Real-time optimal quantum control of mechanical motion at room temperature. Nature, 595. 373–377

[3] Murata J. and Tanaka S., (2015), A review of short-range gravity experiments in the LHC era. Class. Quant. Grav., 32. 033001