2023/01/17 by Wu, Fang-Fei, Shi, Ting-Yun, Tang, Li-Yan
#Atomic Physics (physics.atom-ph) #FOS: Physical sciences
paper · doi:10.48550/arxiv.2301.06740
With the improvement of high-precision optical clock, the higher-order multipolar interaction between atoms and light needs quantitative evaluation. However for the Sr clock, the differential dynamic E2-M1 polarizability at the magic wavelength has contradictions among available theoretical and experimental results. Recently, the new experimental measurement of S. Dörscher \em et al. [arXiv: 2210. 14727] is consistent with measurement of Ushijima \em et al., which poses new challenges to theory and urgently calls for theoretical explanations. In present work, we investigate contributions of negative-energy states to the E2 and M1 polarizabilities. We find that for the M1 polarizability, the contribution from negative-energy states is crucial and dominant. Our new theoretical result for E2-M1 polarizability difference is -7.74(3.92)× 10-5 a.u., which is in good agreement with the recent experiment of S. Dörscher et al., so the inconsistency problem of E2-M1 polarizability in the Sr clock between theory and experiment is eliminated.