A. Yamaguchi, M. S. Safronova, K. Gibble, and H. Katori
We experimentally and theoretically determine the magic wavelength of the (5s2)1S0−(5s5p)3P0 clock transition of 111Cd to be 419.88(14) and 420.1(7) nm. To perform Lamb-Dicke spectroscopy of the clock transition, we use narrow-line laser cooling on the 1S0−3P1 transition to cool the atoms to 6 μK and load them into an optical lattice. Cadmium is an attractive candidate for optical lattice clocks because it has a small sensitivity to blackbody radiation and its efficient narrow-line cooling mitigates higher order light shifts. We calculate the blackbody shift, including the dynamic correction, to be fractionally 2.83(8)×10−16 at 300 K, an order of magnitude smaller than that of Sr and Yb. We also report calculations of the Cd 1P1 lifetime and the ground state C6 coefficient.
Physical Review Letters : https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.123.113201