Chuankun Zhang, a former graduate student within the research group of Jun Ye, a fellow at JILA and the National Institute of Standards and Technology (NIST), has been awarded the 2025 Boeing Quantum Creators Prize. This national honour recognises early-career researchers demonstrating significant advancement in quantum science and engineering. Zhang’s award-winning research focuses on the development of a solid-state optical nuclear clock predicated on the thorium-229 nuclear transition, a development with the potential to redefine precision timekeeping and facilitate new avenues for both fundamental physics research and practical metrology applications. His work, which involved building extreme ultraviolet (XUV) frequency combs for direct laser spectroscopy of thorium nuclei, was highlighted in a 2024 cover article in the journal Nature, detailing the first precision measurement of this nuclear transition directly referenced to an optical atomic clock standard.
Chuankun Zhang’s Innovation
Zhang’s research centres on the thorium-229 nuclear transition, a unique characteristic of this isotope that allows for the potential creation of a highly precise nuclear clock. Unlike conventional atomic clocks which rely on the energy levels of electrons, a nuclear clock leverages the energy levels within the nucleus of an atom. Thorium-229 is particularly promising because it possesses a low-energy nuclear transition that emits extreme ultraviolet (XUV) photons, making it directly accessible with current laser technology. The development of XUV frequency combs was crucial to Zhang’s work, enabling the precise measurement of these XUV photons and, consequently, the frequency of the nuclear transition. This first-ever precision measurement, referenced to an optical atomic clock standard, represents a significant step towards realising a practical nuclear clock based on thorium-229. The research involved not only the development of the necessary laser technology but also the careful selection and preparation of thorium-containing materials to optimise the signal strength and precision of the measurements.
JILA Partnership Details
The research was conducted within the collaborative environment of JILA, a joint institute of the University of Colorado Boulder and NIST. JILA fosters an interdisciplinary approach, bringing together experimental and theoretical physicists to push the boundaries of quantum science. The work benefited from the expertise of Jun Ye’s research group, which specialises in precision measurement and optical atomic clocks. The collaborative spirit extends beyond JILA, with Zhang working closely with collaborators worldwide to further develop material platforms for the nuclear clock and explore its performance in different host materials. This international collaboration is crucial for addressing the challenges associated with material science and optimising the clock’s performance. The institute’s emphasis on both experimental innovation and theoretical insight has been instrumental in driving this research forward.
CU Boulder Physics Implementation
As a graduate student in the Physics department at the University of Colorado Boulder, Zhang’s research was closely integrated with the academic curriculum and benefited from the resources available at the university. The research group actively uses the nuclear clock platform to probe fundamental physics, leveraging its high precision to search for subtle variations in fundamental constants and test the limits of our understanding of the universe. The 2025 Boeing Quantum Creators Prize, which includes a $3,500 honorarium and a commemorative trophy, will be awarded at the annual Chicago Quantum Summit on November 3–4. Zhang presented his findings during a recent colloquium at CU Boulder, highlighting the potential of this new field and the ongoing efforts to improve the performance and stability of the thorium-229 nuclear clock. The research underscores the collaborative and interdisciplinary spirit of JILA and the University of Colorado Boulder, where innovation and insight converge to advance the frontiers of quantum science.
