Interorbital interactions in an SU ( 2 ) ⊗ SU ( 6 ) -symmetric Fermi-Fermi mixturePhys. Rev. A 103, 033315 (2021)

18 March 2021

Photo: UHH/Abeln

High-resolution spectrum of the interspecies interaction peak

We characterize interisotope interorbital interactions between atoms in the ¹S₀ ground state and the ³P₀ metastable state in interacting Fermi-Fermi mixtures of ¹⁷¹Yb and ¹⁷³Yb. We perform high-precision clock spectroscopy to measure interaction-induced energy shifts in a deep three-dimensional optical lattice and determine the corresponding scattering lengths. We find the elastic interaction of the interisotope mixtures ¹⁷³Yb_e−¹⁷¹Yb_g and ¹⁷³Yb_g−¹⁷¹Yb_e to be weakly attractive and very similar, while the corresponding two-body decay coefficients differ by more than two orders of magnitude. By comparing different spin mixtures we experimentally demonstrate the SU(2)⊗SU(6) symmetry of the elastic interactions. Furthermore, we measure the interorbital spin-exchange interaction in ¹⁷¹Yb and confirm its previously observed antiferromagnetic nature.

Read the original article: Abeln et al., Phys. Rev. A 103, 033315 (2021)