Narrow-line Cooling and Determination of the Magic Wavelength of Cd

Abstract

We experimentally and theoretically determine the magic wavelength of the (5s 2 ) 1 S0−(5s5p) 3 P0 clock transition of 111 Cd to be 419.88(14) nm and 420.1(7) nm. To perform Lamb-Dicke spectroscopy of the clock transition, we use narrow-line laser cooling on the 1 S0− 3 P1 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 1 P1 lifetime and the ground state C6 coefficient.

Laser Spectroscopy of the y$^7$P$_J^{\circ}$ states of Cr I

“…The CI+all-order method was demonstrated to produce accurate results for a wide range of atomic properties for atoms and ions with 2 to 4 valence electrons [19][20][21][22]. The main problem in extending this approach to more complicated systems such as Cr is an exponential increase in the number of configurations in the CI expansion with the number of valence electrons.…”

“…Second, these measurements provide a high-precision benchmark for the first application of the configuration interaction (CI) and the linearized coupled cluster method (CI+all-order method) for a system with 6 valence electrons. The CI+all-order method was demonstrated to produce accurate results for a wide range of atomic properties for atoms and ions with 2 to 4 valence electrons [19][20][21][22]. This method has provided precision data for many applications, including development of ultra-precise clocks [19,21,23], studies of fundamental symmetries [24,25], searches for the variation of fundamental constants [26], quantum simulation and computation [27,28], plasma physics [29], nuclear physics [22,30], and many others.…”

“…The CI+all-order method was demonstrated to produce accurate results for a wide range of atomic properties for atoms and ions with 2 to 4 valence electrons [19][20][21][22]. This method has provided precision data for many applications, including development of ultra-precise clocks [19,21,23], studies of fundamental symmetries [24,25], searches for the variation of fundamental constants [26], quantum simulation and computation [27,28], plasma physics [29], nuclear physics [22,30], and many others. It was previously thought to be unfeasible to apply this method to systems such as Cr due to extremely large number of configurations that have to be considered as well as limitation of the initial closed-shell approximation.…”

Van der Waals molecules consisting of a zinc or cadmium atom interacting with an alkali-metal or alkaline-earth-metal atom

“…Here, the main focus has been put on the optical lattice clocks based on strontium [14,15,17], ytterbium [16,18], and mercury [19][20][21] atoms, however, recent proposals have brought attention to two other suitable candidates, zinc and cadmium atoms [22][23][24][25]. Optical lattice clocks based on group-IIB atoms, such as Zn, Cd, or Hg, have been shown to exhibit reduced susceptibility to the black body radiation (BBR) as compared to Sr-or Yb-based clocks [19-22, 24, 26].…”

“…Additionally, zinc or cadmium atom interacting with other atoms may form weakly-bound Van der Waals molecules that may potentially be used as precise probes of new gravity-like forces [53,54]. The ongoing progress in laser trapping and cooling of cadmium atoms [24,[55][56][57] further motivates our investigation.…”