Milligram-scale gravitational coupling measured via microwave optomechanics at millikelvin temperatures
A millikelvin optomechanical resonator measured gravitational attraction between milligram masses, improving sensitivity by two orders of magnitude. The work bridges classical gravity metrology and future quantum-gravity experiments but remains limited to classical states. Further cooling and quantum control are required to probe non-classical gravitational effects.
The setup provides a concrete platform for preparing the test mass in non-classical motional states while retaining gravitational interaction with a macroscopic source. Next steps require integration of ground-state cooling and quantum nondemolition measurements to reach the regime where gravitational entanglement could be tested. Achieving that threshold would demand another factor of ten reduction in decoherence rate within the next five years.
Sources (2)
- [1]Primary Source(https://arxiv.org/abs/2611.08619)
- [2]Supporting Source(https://www.nature.com/articles/s41586-023-06036-3)