Abstract
We report a test of the universality of free fall by comparing the gravity acceleration of the atoms in versus those in , of which the corresponding spin orientations are opposite. A Mach-Zehnder-type atom interferometer is exploited to alternately measure the free fall acceleration of the atoms in these two magnetic sublevels, and the resultant Eötvös ratio is . This also gives an upper limit of for a possible gradient field of the spacetime torsion. The interferometer using atoms in is highly sensitive to the magnetic field inhomogeneity. A double differential measurement method is developed to alleviate the inhomogeneity influence, of which the effectiveness is validated by a magnetic field modulating experiment.
- Received 26 January 2016
DOI:https://doi.org/10.1103/PhysRevLett.117.023001
© 2016 American Physical Society
Physics Subject Headings (PhySH)
Synopsis
Skydiving Spins
Published 6 July 2016
Atom interferometry shows that the free-fall acceleration of rubidium atoms of opposite spin orientation is the same to within 1 part in 10 million.
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