Our research is in the field of theoretical atomic physics. Our main focus is on high-precision atomic structure calculations, and how atomic processes can be used for testing fundamental theories, including probing for physics beyond the standard model and searching for dark matter.

Available projects at UQ (honours, PhD)

Note that details of ongoing/available projects change regularly, so if you are interested in doing research along any of these lines, please feel free to contact us to discuss specific options:

• Dr. Jacinda Ginges - j.ginges [at] uq.edu.au
• Dr. Benjamin Roberts - b.roberts [at] uq.edu.au

Tests of the standard model of particle physics and searches for new physics at the precision frontier.

• This includes calculations of atomic parity violation (APV) and time-reversal-violating electric dipole moments (EDMs) for interpretation of precision atomic experiments. Studies of violations of fundamental symmetries in atoms provide some of the most precise tests of the standard model, and they can help to answer some of the big questions of science, including: why is there a dominance of matter over antimatter in our Universe? What is the nature of dark matter? Atomic calculations are needed to interpret precision measurements in terms of fundamental particle physics parameters. It remains a challenge to increase the accuracy of calculations in order to maximise the discovery potential of atomic experiments, and this is a focus of our group.

Development of precision atomic structure theory in heavy atoms.

• This includes development of all-orders atomic many-body methods and computer codes, and the combination of quantum electrodynamics and many-body theory. Improving the accuracy and capability of state-of-the-art atomic precision theory for heavy atoms is important for a number of different areas, including in studies of violations of fundamental symmetries (APV and EDMs), in probing the structure of the nucleus, in the study of the physical properties of heavy and superheavy elements, and in metrology including atomic clocks.

Probing nuclear structure through precision atomic physics.

• Details of the structure of the nucleus may be revealed in precision studies of the hyperfine structure (HFS) in atoms. Studies of the HFS play an important role in nuclear and atomic physics, as well as in metrology. Indeed, the hyperfine splitting in the ground state of atomic Cs has been measured very precisely, and it defines the unit for time, the second. Comparison of theoretical and measured values of the HFS allows one to probe the structure of the nucleus and the quality of the atomic wave functions in the nuclear region. Our interest in this area is mulit-faceted, and we are devising new ways to better probe and model nuclear magnetic structure in heavy atoms.

Dark matter induced atomic ionisation.

• Develop and test atomic methods for calculating dark matter interactions with atoms. This includes atomic excitation and ionisation caused by the scattering and/or absorption of dark matter particles by atoms. The project will involve aspects of quantum mechanics (elementary atomic theory, scattering theory) and particle astrophysics (application to dark matter direct detection experiments, and interpretation of results in terms of dark matter and particle physics models). It will also involve some basic programming (in c++ and/or python), though no prior knowledge of programming is required. For some details, see:
  • “Electron-interacting dark matter: Implications from DAMA/LIBRA-phase2 and prospects for liquid xenon detectors and NaI detectors.” Physical Review D, 100, 063017 (2019) [http://arxiv.org/abs/1904.07127]

High-accuracy atomic physics calculations.

• Atomic physics calculations involve treating the many-electron atomic Hamiltonian approximately. In order to achieve high accuracy, a number of many-body effects need to be taken into account using perturbation theory. One such class of effects, known as “ladder diagrams”, are missing from some calculations. Though small, these corrections seem to be important in some cases. The ladder-diagram method has been applied previously to energies with high success (see: Physical Review A, 78, 042502.) The plan here is to extend this method to include “ladder diagram” corrections directly into atomic wavefunctions. These wavefunctions can then be used to compute relevant atomic properties (for example, hyperfine splittings, transition rates, lifetimes etc.). The project will involve aspects of quantum mechanics (elementary atomic theory) and numerical methods (application of existing code libraries to new problems in atomic physics). It will also involve some basic programming (in c++, python and/or fortran), though no prior knowledge of programming is required.

We have other projects available in our group, including studies of the properties of the superheavy elements — those with Z > 104, up to and beyond the heaviest elements of the Periodic Table — and in the area of metrology, in particular atomic clocks.