Research

"How do nuclear structure phenomena emerge from quantum chromodynamics?"

I aim to answer this question by precisely investigating the properties of atomic nuclei by measuring their influence upon electrons that are bound to them in atoms and molecules. This is achieved through irradiating beams of radioactive atoms with intricate sequences of laser pulses, whereby electrons are sequentially excited and then ionized to reveal the electromagnetic properties of the nuclei at the heart of them. These measurements offer multiple complementary insights into the single-particle and collective nature of nuclei which are then used as stringent tests for the latest advancements in nuclear structure theory. I use the newly established Resonance Ionization Spectroscopy Experiment (RISE) setup at BECOLA for these experiments to enable higher-sensitivity studies of nuclei at the extremes of existence produced by FRIB. 

Another theme of my research involves advancing studies of radioactive molecules. Despite their more complex structures compared to atoms, radioactive molecules offer distinct discovery potential in multiple areas of science. This is particularly true in the field of fundamental symmetries, where molecules containing octupole-deformed radioactive nuclei are premier candidates for next-generation experiments aiming to answer, "Why is there far more matter compared to antimatter in the universe?" I am developing a general approach to cool and slow beams of radioactive molecules such that their rotational and hyperfine structures can be directly manipulated with microwave radiation, realizing a thousand times improvement in experimental precision compared to the current state of the art. This leap forward in precision will enable the exploration of more subtle properties of atomic nuclei, including the distribution of nuclear magnetization and magnetic octupole moment, which are poorly understood at present, offering a new window into our understanding of the atomic nucleus.

The magnitude of different effects in the molecular structure of radium monofluoride due to the properties of the radium nucleus.

Biography

Born in Leicester in the United Kingdom, I studied physics at the University of Manchester, the birthplace of nuclear physics. After my undergraduate studies, I continued at the university embarking upon a PhD in the Nuclear Physics Group in which I moved to work full-time at the European Organization for Nuclear Research (CERN) in Geneva, Switzerland. During this time, I advanced the capabilities of ultrasensitive laser spectroscopy techniques performing experiments on radioactive isotopes at the ISOLDE facility. After my PhD, I was awarded a CERN Fellowship where I worked as part of the Resonance Ionization Laser Ion Source and was involved with the first laser spectroscopy study of a radioactive molecule. I then became a postdoctoral associate at the Massachusetts Institute of Technology, initially remaining at CERN to lead the next experiments on radioactive molecules before moving to the United States. After relocating, I worked to develop and implement a new laser spectroscopy setup at FRIB, where I became a member of faculty in 2025. My current research is focused on elucidating the properties of atomic nuclei through investigating their influence upon electrons that are bound to them in atoms and molecules.

How students can contribute as part of my research team

Students are the lifeblood of academic research and play a crucial role in all aspects of my team’s activities. This ranges from planning and undertaking experiments in addition to developing cutting-edge techniques that open up new scientific opportunities. The experiments that we work on form a sweet spot in terms of their scale, in which students can gain hands-on experience in a diverse range of areas encompassing lasers, optics, ultra-high vacuum, ion optics, traps and detectors as well as data acquisition and analysis. In addition, as our work blurs the boundaries between nuclear and atomic, molecular and optical physics, there are plentiful opportunities for interdisciplinary collaboration. By the end of their studies, students working with me will have developed a wide-ranging scientific toolkit enabling them to tackle complex and challenging problems in a rigorous manner in their future careers.

The most exciting aspect of my research at FRIB relates to the wonderful people who I get to collaborate with on a day-to-day basis at the facility.

Scientific publications

• Laser spectroscopy for the study of exotic nuclei, X. F. Yang, S. J. Wang, S. G. Wilkins and R. F. Garcia Ruiz, Progress in Particle and Nuclear Physics 129, 104005 (2023).
• Precision spectroscopy and laser cooling scheme of a radium-containing molecule, S M. Udrescu, S. G. Wilkins, A. A. Breier, M. Athanasakis-Kaklamanakis, R. F. Garcia Ruiz, M. Au, I. Belošević, R. Berger, M. L. Bissell, C. L. Binnersley, A. J. Brinson, K. Chrysalidis, T. E. Cocolios, R. P. de Groote, A. Dorne, K. T. Flanagan, S. Franchoo, K. Gaul, S. Geldhof, T. F. Giesen, D. Hanstorp, R. Heinke, Á. Koszorús, S. Kujanpää, L. Lalanne, G. Neyens, M. Nichols, H. A. Perrett, J. R. Reilly, S. Rothe, B. van den Borne, A. R. Vernon, Q. Wang J. Wessolek, X. F. Yang, C. Zülch, Nature Physics 20, 202-207 (2024).