Reported experiment tests gravity’s equivalence principle with a quantum condensate

A quantum condensate on two paths

The report describes a Quantum Galileo Interferometer that split a chilled cloud of rubidium atoms, prepared as a Bose-Einstein condensate, into two wave-packet paths. One was held stationary relative to the laboratory while the other followed a free-fall trajectory. After the paths were recombined, the reported shift matched the predicted result for the equivalence principle.

The equivalence principle had been tested with macroscopic systems, but how it applied to quantum objects in a direct experiment remained uncertain.

A report says an interferometer experiment with a Bose-Einstein condensate found the measured phase shift matched the equivalence principle’s prediction in the quantum regime.

The reported phase shift matched the equivalence principle’s prediction. The report explicitly distinguishes that result from unifying quantum mechanics with gravity or proving that gravity itself is quantum.