Actualités > Publication

Differential polarizability of the strontium intercombination transition at 1064.7 nm

The « Relaxation dynamics in quantum gases » team from the Charles Fabry Laboratory recently published an article in the Physical Review Journals.

The authors :

• Romaric JOURNET
• Félix FAISANT
• Sanghyeop LEE
• Marc CHENEAU

We measure the scalar, vector, and tensor components of the differential dynamic polarizability of the strontium intercombination transition at 1064.7 nm. We compare the experimental values with the theoretical prediction based on the most recently published spectroscopic data, and find a very good agreement. We also identify a close-to-circular “magic” polarization where the differential polarizability strictly vanishes, and precisely determine its ellipticity. Our work opens new perspectives for laser cooling optically trapped strontium atoms and provides a benchmark for atomic models in the near-infrared spectral range.

© Journet et al.,Phys. Rev. A 110, 032819 (2024)

Differential Stark shift of the ¹S₀ – ³P₁ , m = −1 strontium transition as we vary the ellipticity of the Stark beam polarization. The direction of the atomic dipole (x) is fixed by the external magnetic field B and is parallel to the Stark beam propagation axis. The ellipticity of the Stark beam polarization u is controlled by the orientation of a quarter-wave plate. The differential Stark shift is found to be zero for a magic ellipticity C_magic = +0.847 ± 0.023 (red dots), corresponding to the latitude +57.9◦ on the Poincaré sphere (red circle).