Levitated Nanospheres for Submicron Gravity Tests in Cryogenic EHV Environment*

Levitated Nanospheres for Submicron Gravity Tests in a Cryogenic EHV Environment

Testing established physical theories in yet unexplored parameter regimes is at the heart of the scientific enterprise. Recently, levitated nanoobjects under extremely high vacuum (EHV) and cryogenic conditions, have been identified as a promising experimental platform for a variety of tests of the Standard Model (SM) as well as surface forces [1], such as short-range Newtonian Gravity tests, matter-wave neutrality or Casimir-Polder forces at cryogenic temperature.  

Such strongly decoupled optomechanical systems are only subject to laser noise, thermal collisions, and vibrations. By working in a vibration-stabilized, cryogenic EHV environment (<1e-10 millibar), the particle is only subject to laser shot noise. Zeptonewton sensitivity even under moderate pressures has been demonstrated in our group [3].

I will report on the experimental realization and ideas of our new setup, where we achieve pressures well below 1e-10 millibar and a temperature of 6.4K. Experimental and computational results on particle launches in EXV, the center of mass cooling, and characterization of the short-range interactions will be presented.

[1] Moore, David C., and Andrew A. Geraci. "Searching for new physics using optically levitated sensors." Quantum Science and Technology 6.1 (2021): 014008.

[2] Ranjit, Gambhir, et al. "Zeptonewton force sensing with nanospheres in an optical lattice." Physical Review A 93.5 (2016): 053801.