A novel theory has emerged, transforming our understanding of how light and matter interact at the quantum level, enabling researchers to define the precise shape of a single photon for the very first time. Research led by the University of Birmingham and published in Physical Review Letters dives deep into the intricate nature of photons— the fundamental particles of light.
This study reveals extraordinary insights into how photons are emitted by atoms or molecules and shaped by their environments. This complex interaction gives rise to limitless ways light can exist and travel through its surroundings. However, the sheer number of possibilities makes modeling these interactions exceptionally challenging, a formidable puzzle that quantum physicists have been striving to solve for decades.
Through innovative grouping of these possibilities, the Birmingham team has developed a comprehensive model that elucidates not only the dynamics between the photon and its emitter but also captures how energy from this interaction propagates into the remote ‘far field.’
Moreover, their advanced calculations have allowed them to create a vivid visualization of the photon itself, representing a significant leap in our understanding of light.
First author Dr Benjamin Yuen, in the University’s School of Physics, explained: “Our calculations enabled us to convert a seemingly insolvable problem into something that can be computed. And, almost as a by-product of the model, we were able to produce this image of a photon, something that hasn’t been seen before in physics.”
This research is significant as it paves the way for novel studies in quantum physics and materials science. By accurately characterizing how photons engage with matter and their surrounding elements, researchers can create innovative nanophotonic technologies that have the potential to transform secure communication, pathogen detection, or the regulation of chemical reactions at a molecular scale, for instance.
Co-author Professor Angela Demetriadou, also at the University of Birmingham, said: “The geometry and optical properties of the environment have profound consequences for how photons are emitted, including defining the photon’s shape, color, and even how likely it is to exist.”
Dr Benjamin Yuen added: “This work helps us to increase our understanding of the energy exchange between light and matter, and secondly to better understand how light radiates into its nearby and distant surroundings. Lots of this information had previously been thought of as just ‘noise’ – but there’s so much information within it that we can now make sense of and make use of. By understanding this, we set the foundations to be able to engineer light-matter interactions for future applications, such as better sensors, improved photovoltaic energy cells, or quantum computing.”
Journal reference:
- Ben Yuen, and Angela Demetriadou. Exact Quantum Electrodynamics of Radiative Photonic Environments. Physical Review Letters, 2024; DOI: 10.1103/PhysRevLett.133.203604