Photo credit: Romain Bara

One of the most precise tools devised by humankind is the optical atomic clock, one of which is under development here at UWA. Such clocks can test numerous aspects of physics, e.g. the constancy of fundamental constants, the isotropy of space and general relativistic effects. More recently, they have been used to search for Dark Matter transients and Dark Matter force mediators.

Our work involves a computational component as well as experimental. Recent computational work included atomic structure calculations for Yb (Phys. Rev. A, 104, 022806, 2021), which is relevant to the search for phenomena lying beyond the Standard Model. Atomic clocks can always be improved upon, so we have continual development on the experimental side, which involves laser frequency control, atom manipulation systems, optical setups, circuit design, optoelectronic control systems and coding. The lab commenced in 2013.

Congratulations to **Jesse Schelfhout** on receiving WA’s 2022 Rhodes Scholarship. Jesse completed his Physics Honours and Master degrees in the Atomic Clock Lab.

The aim is to increase the versatility of a clock-synchronised frequency-to-voltage converter. This has commercial potential in laser stabilisation applications (and perhaps beyond).

Femto-second lasers have applications ranging from tooth enamel ablation, to atomic clock read-outs, to high speed communications. Here we are building a femto-second laser to enhance the properties of an existing frequency comb used for clock read-out and laser stabilisation.

The aim is to trap Yb in a focused laser beam at the magic wavelength. This will increase the the accuracy of our Yb clock some thousand-fold.

Our optical trap simulator has been heavily tested for optical lattice trapping in 1D, but further testing/optimisation is required for the single-beam optical trapping and 2D trapping. This is relevant to most ultracold atom experiments.

The aim is to compute multi-configuration Dirac-Hartree-Fock calculations for atomic levels relevant to atomic clocks. The calculations yield important atomic and nuclear parameters, such as hyperfine structure constants and isotope shift parameters. Computational software is freely available for these calculations.

Part of the ytterbium clock at UWA. Photo credit: Sean Middleton.

Phys. Rev. A, 104, 022806 (2021)

J. Opt. Soc. Am. B, 38, 36 (2021)

Phys. Rev. A, 100, 042505 (2019)

Appl. Opt., 58, 3128 (2019)

J. S. Schelfhout and J. J. McFerran, “Multiconfiguration Dirac-Hartree-Fock calculations for Hg and Cd with estimates for unknown clock-transition frequencies”, Phys. Rev. A, 105, 022805 (2022).

https://doi.org/10.1103/PhysRevA.105.022805

J. S. Schelfhout and J. J. McFerran, “Isotope shifts for ^{1}S_{0} - ^{3}P_{0,1} Yb lines from multiconfiguration Dirac-Hartree-Fock calculations”, Phys. Rev. A, 104, 022806 (2021).

https://doi.org/10.1103/PhysRevA.104.022806

J. S. Schelfhout, L. D. Toms-Hardman and J. J. McFerran, “Fourier transform detection of weak optical transitions in atoms undergoing cyclic routines”, Appl. Phys. Lett, 118, 014002 (2021). ** Editor's Pick**

https://doi.org/10.1063/5.0034217

R. S. Watson and J. J. McFerran, “Simulation of optical lattice trap loading from a cold atomic ensemble”, J. Opt. Soc. Am. B, 38, 36 (2021).

https://doi.org/10.1364/JOSAB.408521

P. E. Atkinson, J. S. Schelfhout and J. J. McFerran, “Hyperfine constants and line separations for the ^{1}S_{0} - ^{3}P_{1} intercombination line in neutral ytterbium with sub-Doppler resolution”, Phys. Rev. A, 100, 042505 (2019).

https://link.aps.org/doi/10.1103/PhysRevA.100.042505

F. C. Reynolds and J. J. McFerran, “Optical frequency stabilization with a synchronous frequency-to-voltage converter”, Appl. Opt., 58, 3128 (2019). ** Editor's Pick**

https://www.osapublishing.org/ao/abstract.cfm?uri=ao-58-12-3128

A. Guttridge, S. A. Hopkins, M. D. Frye, J. J. McFerran, J. M. Hutson, and S. L. Cornish. “Production of ultracold Cs*Yb molecules by photoassociation”, Phys. Rev. A, 97, 063414 (2018).

https://link.aps.org/doi/10.1103/PhysRevA.97.063414

J. J. McFerran, “Laser stabilization with a frequency-to-voltage chip for narrow-line laser cooling”, Opt. Lett., 43, 1475 (2018).

https://www.osapublishing.org/ol/abstract.cfm?uri=ol-43-7-1475

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john.mcferran @ uwa.edu.au

Department of Physics, The University of Western Australia

35 Stirling Highway, Crawley, WA 6009, Australia