What shape does a photon have?

A new model developed by physicists in the United Kingdom provides a full quantum description of the point at which light and matter interact, preserving a picture of how the interaction continues to influence the particle as it zooms through a tangle of electric fields. “Calculations allowed us to turn a seemingly intractable problem into something that could be calculated,” says theoretical physicist Benjamin Ewen from the University of Birmingham. Channel 24 was introduced to his report.

Almost as a by-product of the model, we were able to create an image of a photon, something never before seen in physics.
– added the scientist.

The photon, which has the characteristics of both a wave rippling in an immaterial ocean and a massless object approaching its speed limit, challenges our imagination with its dual nature. Its existence is a mystery; It is something that can be represented with extraordinary precision by the mathematics of probability, but it does not have a suitable analogy that we can use to imagine what it might look like in our world of shapes, sizes, and colors.

But some properties of light can translate into something familiar. embedded in the quantum code known as the wave function rules that determine the limits of the photon’s impact on the environment.

What we perceive as the faint glow of a neon sign or the sun’s rays on a summer day is, in the language of electromagnetism, the interchange between atoms. As electrons move in their orbits, they emit corresponding units of energy known as photons.

Scientists say advances in our technological ability to control and direct this electromagnetic “conversation” are revealing the incredible complexities of how light passes through the material universe. This journey can no longer be understood as a one-way passage of energy from the point of emission to the point of destination.. Rather, its quantum nature preserves a kind of memory that keeps returning to its path in what physicists call non-Markov dynamics.

The geometry and optical properties of the medium have profound consequences for how photons propagate, including determining their shape, color, and even probability of existence.
– added Angela Demetriadou, a scientist at the University of Birmingham.

To better understand these quantum rules for a photon’s non-Markovian journey through time and matter, Yuen and Demetriadou developed a unique model that describes the open environment in which light interacts immediately after being emitted by atoms in silicon nanoparticles.

Their theories not only described with unprecedented accuracy the propagation of light from an initial point, but also determined the “noise” of the interactions. correctly described the gradients of the intensity of the field surrounding the light quantum. Thus, by understanding where this field begins and reaches where it reaches, scientists were able to describe the shape of a photon.

Photon shape with labeled electromagnetic fields / Photo: Benjamin Yuen

As our desire for smaller, faster, finer and more precise technologies increases, the need to accurately predict the quantum signatures left behind by photons will become increasingly important.

“By understanding this, we lay the foundations for engineering the interaction of light and matter for future applications such as better sensors, advanced photovoltaics or quantum computing,” concludes Benjamin Yuen.