Researchers at Imperial College London (UK) have coupled light to a single electron, combining the properties of both photons and electrons, which could lead to a new kind of optical circuit and change the way we conceive light.
“Light is a collection of many photons,” says Dr Vincenzo Giannini, Leverhulme lecturer on the theory of metamaterials/plasmonics in the Department of Physics at Imperial College London. “We discovered that in materials called ‘topological insulators,’ photons can bind to an electron, giving rise to a new 'mind of light.’ “ The researcher adds that the discovery could find various applications in quantum technology.
For instance, the scientific advance could allow researchers to study quantum physical phenomena, which govern sub-atomic particles, on a visible scale.
Taking down the hurdles of material imperfections
Light generally interacts with multiple electrons in an on the surface of a material. However, theoretically modeling the behavior of topological insulators, the new class of materials, indicates that light could interact with only a single electron on the surface of the material — a coupling that would merge properties of light with properties of the electron. Rather than traveling in a straight line, light could follow the path of the electron on which it is piggybacking.
Giannini’s team modeled this interaction around a nanoparticle made of a topological insulator, which revealed that the light takes the property of the electron and circulates the particle. In return, the electron adopts some properties of the photons.
Here is the very promising part of this research: Giannini and his colleagues discovered that while light traveling along the surface of a material, such as electrical circuits, will normally stop at a defect, in this experiment, an electron coming upon an imperfection in the surface of a topological insulator will press ahead, with the aid of the light.
This phenomenon could make photonic circuits more robust and less vulnerable to disruptions.
Important impact on quantum technology
Giannini says this research will have significant impact on the way we conceive light. Topological insulators, though a fairly recent discovery, are already providing researchers with new phenomena to study and new ways to explore important concepts in physics. His team, collaborating with experimental physicists, is now working toward observing the modeled phenomena. What is more, Giannini says, “We want to show that the exotic property of matter described by quantum mechanics can be observed at room temperature for macroscopic objects.”
The study “Single-electron induced surface plasmons on a topological nanoparticle,” which Giannini co-authored, was published in Nature Communications.
Written by Sandra Henderson, research editor, Novus Light Technologies Today