Observation of an Inner-Shell Orbital Clock Transition in Neutral Ytterbium Atoms

Taiki Ishiyama, Koki Ono, Tetsushi Takano +2

We observe a weakly allowed optical transition of atomic ytterbium from the ground state to the metastable state $4f^{13}5d6s^2(J=2)$ for all five bosonic and two fermionic iso…