Improved bounds on Lorentz violation from composite pulse Ramsey spectroscopy in a trapped ion.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 36437241.
- Also identified by DOI 10.1038/s41467-022-34818-0 and PMC identifier 9701673.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
In attempts to unify the four known fundamental forces in a single quantum-consistent theory, it is suggested that Lorentz symmetry may be broken at the Planck scale. Here we search for Lorentz violation at the low-energy limit by comparing orthogonally oriented atomic orbitals in a Michelson-Morley-type experiment. We apply a robust radiofrequency composite pulse sequence in the <sup>2</sup>F<sub>7/2</sub> manifold of an Yb<sup>+</sup> ion, extending the coherence time from 200 μs to more than 1 s. In this manner, we fully exploit the high intrinsic susceptibility of the <sup>2</sup>F<sub>7/2</sub> state and take advantage of its exceptionally long lifetime. We match the stability of the previous best Lorentz symmetry test nearly an order of magnitude faster and improve the constraints on the symmetry breaking coefficients to the 10<sup>-21</sup> level. These results represent the most stringent test of this type of Lorentz violation. The demonstrated method can be further extended to ion Coulomb crystals.