Researchers at the University of Birmingham have developed a mathematical framework that precisely defines the shape of a single photon, marking a significant advancement in quantum physics. This new approach enhances our understanding of light-matter interactions at the quantum level.
The study addresses a longstanding challenge in quantum physics: accurately modeling the myriad ways light interacts with and traverses its environment. The team introduced a method called “pseudomode transformation,” which organizes the infinite possibilities of these interactions into distinct, manageable sets. This technique enables precise tracking of how light behaves near its source and how its energy propagates through surrounding space.
Professor Angela Demetriadou from the University of Birmingham highlighted the impact of environmental factors on photon characteristics, stating, “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.”
To validate their model, the researchers examined the interaction between a quantum emitter, such as an atom or molecule, and a silicon sphere approximately one micrometer in diameter—about one-hundredth the width of a human hair. This setup revealed a complex array of quantum interactions that the new mathematical framework could accurately describe.
Dr. Benjamin Yuen, the study’s lead author, emphasized the practical implications of their findings: “Our calculations enabled us to convert a seemingly unsolvable 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 not only enhances our comprehension of energy exchange between light and matter but also provides insights into how light radiates into its nearby and distant surroundings. Dr. Yuen noted that information previously considered “noise” can now be understood and utilized, opening new avenues for technological advancements in fields like quantum computing and communication.
The study’s findings were published in the journal Physical Review Letters. This breakthrough offers a deeper understanding of the fundamental nature of light and its interactions, potentially leading to significant technological innovations.
