Strongly enhanced effects of Lorentz symmetry violation in entangled Yb+ ions

Exotic theories predict the violation of Lorentz symmetry, which could potentially be spotted in low-energy experiments. Using ytterbium ions could improve the current sensitivity bounds by five orders of magnitude. A number of theories aiming at unifying gravity with other fundamental interactions, including field theory, suggest the violation of Lorentz symmetry1,2,3. Whereas the energy scale of such strongly Lorentz-symmetry-violating physics is much higher than that attainable at present by particle accelerators, Lorentz violation may nevertheless be detectable via precision measurements at low energies2. Here, we carry out a systematic theoretical investigation to identify which atom shows the greatest promise for detecting a Lorentz symmetry violation in the electron–photon sector. We found that the ytterbium ion (Yb+) is an ideal system with high sensitivity, as well as excellent experimental controllability. By applying quantum-information-inspired technology to Yb+, we expect tests of local Lorentz invariance (LLI) violating physics in the electron–photon sector to reach levels of 10−23—five orders of magnitude more sensitive than the current best bounds4,5,6.