Some of the biggest open questions in modern physics concern the limits of the Standard Model and General Relativity. The nature of dark matter and dark energy remains unknown, and many theories attempting to tackle this problem predict that the fundamental constants may vary in space or time. Atomic clocks provide an exceptionally sensitive way of testing this possibility. Their reach is ultimately determined not only by how precisely they can measure frequency, but also by how strongly their…
transitions respond to changes in the fundamental constants. This PhD project aims to develop a new type of atomic clock based on highly charged ions (HCIs). You will work towards the first clock based on highly charged californium (Cf17+), whose exceptional sensitivity to variations of the fine-structure constant makes it a powerful probe of physics beyond the Standard Model. The project will combine HCI production and manipulation with cryogenic ion trapping, laser cooling, precision spectroscopy and quantum-logic techniques. Ultimately, the new clock will be compared with an optical strontium clock to search for temporal variations of the fine-structure constant and signatures of ultralight dark matter and other new physics. You will join our experimental team at the University of Birmingham, where we have built the UK's first platform for highly charged ions. We have already demonstrated the production, charge selection, transport, trapping and sympathetic cooling of HCIs inside laser-cooled Ca+ Coulomb crystals, providing the experimental foundation for the project. The work will range from producing and trapping Cf17+ to developing quantum-logic spectroscopy and an ultra-stable laser for the clock transition. You will also spend approximately six months with our collaborators at MPIK Heidelberg, contributing to the first precision measurements of the atomic structure of Cf HCIs. The project will give you hands-on experience across a broad range of experimental physics, including cryogenics, ultra-high vacuum, charged-particle optics, laser cooling, ion trapping, precision laser spectroscopy, quantum logic and atomic-clock technology. It sits at the interface between atomic physics, quantum technology and fundamental physics, with the goal of creating a new precision system capable of probing unexplored regimes of physics beyond the Standard Model.
