Scientists say they have discovered the shape of individual photons

It’s “something that hasn’t been seen before in physics.”

Everything is illuminated

Be relieved, folks: a fascinating new paper has emerged that describes the shape of a single photon, the smallest possible form of energy in an electromagnetic field commonly known as light.

The work, published as a study in the journal Physical Assessment Lettersgoes into great detail to predict how these light quanta are emitted by atoms and defined by their environment. There are limitless possibilities for how these interactions might unfold, but the researchers say they have developed a practical method for predicting them.

“Our calculations have allowed us to turn a seemingly unsolvable problem into something that can be calculated,” lead author Benjamin Yuen, a physicist at the University of Birmingham in Britain, said in a statement. “And almost as a byproduct of the model, we were able to produce this image of a photon, something that hasn’t been seen before in physics.”

Shaping

Assigning a specific shape to a photon is a difficult task because these massless elementary particles exhibit wave-particle duality, a curious property of objects inhabiting the quantum realm, which is governed by ghostly uncertainties.

This means that scientists think photons behave as both particles and waves depending on how they are observed. Moreover, photons are also understood as excitations in an electromagnetic field, or as a ripple of discrete energy.

In short, they are very difficult to determine, and to complicate matters further, there are infinite ways in which light can interact with its environment and with the atoms that emit them.

But the researchers say they’ve been able to get around this by reducing those possibilities to separate sets using some classical mechanics – or dividing them into ‘pseudomodes’ – thereby streamlining the way they think about the photon interactions.

Going the distance

The advantage of modeling a photon in this way, according to the researchers, is that it can accurately describe how the tiny particles move into a remote region of the electromagnetic field around an object known as the far field. Previous methods separated the near field from the far field, creating an incomplete picture of light systems at the quantum level.

“This work helps us to advance our understanding of the energy exchange between light and matter, and secondly, to better understand how light radiates to its near and distant environment,” Yuen said. “A lot of this information was previously seen as just ‘noise,’ but there’s so much information in it that we can now understand and use.”

This new understanding has very practical implications. For quantum physicists and materials scientists, it could transform the development of nano-optical technology, leading to “better photovoltaic energy cells, or quantum computing,” Yuen said, as well as advances in communications technology.

And let’s be honest: it’s also an aesthetic pleasure.