2025/07/11 by Wang, S. -Z., Wang, S. -B., Tao, Z. -J. +2
#Atomic Physics (physics.atom-ph) #FOS: Physical sciences
paper · doi:10.48550/arxiv.2507.08278
The response of an atom to external electric and magnetic fields can reveal fundamental atomic properties. It has long been verified that, in a static magnetic field, those atomic energy levels with hyperfine interactions shift according to the Breit-Rabi formula, which introduces nonlinear dependence on the magnetic field. On the other hand, the corresponding Breit-Rabi dependence on a static electric field has not been observed before due to a combination of experimental challenges. Here we precisely measure the Stark shift of the 6s2 1S0 ↔ 6s6p 1P1 transition of 171Yb (I = 1/2) with cold atoms held by an optical dipole trap in a static electric field up to 120 kV/cm. We observe the electric Breit-Rabi effect displaying high-order (E4 and E6) DC Stark shifts. These effects arise from the influence of the strong electric field on hyperfine interactions.