By use of the grasp2018 package we perform multiconfiguration Dirac-Hartree-Fock (MCDHF) calculations with configuration interaction (CI) for the ¹S₀ and ³P_0,1 levels in neutral cadmium and mercury. By supplying the resultant atomic state functions to the ris4 program, we evaluate the mass- and field-shift parameters for the ¹S₀−³P₀ (clock) and¹S₀−³P₁ (intercombination) lines. We make revised estimates of the nuclear charge parameters λ^A,A′ and differences in mean-square charge radii δ(r²)^A,A′ for both elements and point out a discrepancy with tabulated data for Cd. In constructing a King plot with the Hg lines we examine the second-order hyperfine interaction for the ³P_0,1 levels. Isotope shifts for the clock transition have been estimated, from which we predict the unknown clock line frequencies in the bosonic Hg isotopes and all the naturally occurring isotopes of Cd

Relativistic multiconfiguration Dirac-Hartree-Fock calculations with configuration interaction are carried out for the 1S0 and 3Po0,1 states in neutral ytterbium by use of the available grasp2018 package. From the resultant atomic state functions and the ris4 program, we evaluate the mass- and field-shift parameters for the 1S0−3Po0 (clock) and 1S0−3Po1 (intercombination) lines. We present improved estimates of the nuclear charge parameters λA,A′ and differences in mean-square charge radii δ⟨r2⟩A,A′ and examine the second-order hyperfine interaction for the 3Po0,1 states. Isotope shifts for the clock transition have been estimated by three largely independent means from which we predict the unknown clock-line frequencies in bosonic Yb isotopes. Knowledge of these line frequencies has implications for King-plot nonlinearity tests and the search for beyond-standard-model signatures.

We demonstrate a means of detecting weak optical transitions in cold atoms that undergo cyclic (preparation, probing, and detection) routines with improved sensitivity. The gain in sensitivity is made by probing atoms on alternate cycles of a repeated experimental sequence, leading to regular modulation of the ground state atom population when at the resonance frequency. The atomic transition is identified by conducting a fast Fourier transform via an algorithm or instrument. We find an enhancement of detection sensitivity compared to more conventional scanning methods of ∼20 for the same sampling time, and can detect contemporary clock lines with fewer than 103 atoms in a magneto-optical trap. We apply the method to the (6𝑠2) 1𝑆0−(6𝑠6𝑝) 3𝑃0 clock transition in 171Yb and 173Yb. In addition, the ac-Stark shift of this line in 171Yb is measured to be 0.19(3) kHz W−1 m2 at 556 nm.

We model the efficiency of loading atoms of various species into a one-dimensional optical lattice from a cold ensemble, taking into account the initial cloud temperature and size, the lattice laser properties affecting the trapping potential, and the atomic parameters. Stochastic sampling and dynamical evolution are used to simulate the transfer, leading to estimates of transfer efficiency for varying trap depth and profile. Tracing the motion of the atoms also enables the evaluation of the equilibrium temperature and site occupancy in the lattice. The simulation compares favorably against a number of experimental results and is used to compute an optimum lattice-waist-to-cloud-radius ratio for a given optical power.

Between a frequency comb mode and a continuous-wave (cw) laser, we demonstrate that a frequency-to-voltage converter can be used to transfer frequency instability in the 10−14 range for integration times 𝜏 between 0.25 and 2100 s. The technique is relevant when the optical beat between laser signals is weak and a high level of frequency stability is required both in the short term and long term, as in the case of laser cooling with very narrow transitions. The impressive stability transfer arises through the use of a synchronous voltage-to-frequency converter that relies on an external CMOS oscillator. Aided by an atomic reference to the frequency comb, the method grants long-term stability to the cw laser, superior to that achieved with most optical cavities.

We report the production of ultracold heteronuclear Cs*Yb molecules through one-photon photoassociation applied to an ultracold atomic mixture of Cs and Yb confined in an optical dipole trap. We use trap-loss spectroscopy to detect molecular states below the Cs(2P1/2)+Yb(1S0) asymptote. For 133Cs174Yb, we observe 13 rovibrational states with binding energies up to ~500GHz. For each rovibrational state we observe two resonances associated with the Cs hyperfine structure and show that the hyperfine splitting in the diatomic molecule decreases for more deeply bound states. In addition, we produce ultracold fermionic 133Cs173Yb and bosonic 133Cs172Yb and 133Cs170Yb molecules. From mass scaling, we determine the number of vibrational levels supported by the 2(1/2) excited-state potential to be 154 or 155.

We use integrated circuit-based frequency-to-voltage conversion of a frequency comb beat signal as the means for laser frequency stabilization that is suitable for narrow-line laser cooling. The method is compared to an atomic beam lock where the laser frequency instability for the new scheme shows an improvement of 2 orders of magnitude at sub-1 s and grants a lock-capture range that is approximately 30 times greater. We employ the locking method on a 1111.6 nm laser that is frequency doubled and used in a dual-wavelength magneto-optical trap for Yb171 atoms, producing atomic cloud temperatures of ~20 μK.