A feat worthy of science fiction
Imagine for a moment: light that behaves at once like a solid and like a fluid. Matter made of photons, able to flow without resistance while forming a rigid, crystalline structure. No, this is not a scene out of a science-fiction film, but a genuine scientific breakthrough, achieved recently by Italian researchers at the National Research Council (CNR).
What is a supersolid?
A supersolid is an exotic state of matter. It combines two properties that seem, on the face of it, incompatible:
- The structural rigidity of a crystalline solid, with atoms (or particles) arranged in a regular pattern.
- The perfect fluidity of a superfluid, able to flow without friction, without losing energy.
Until now, this type of state had been observed in extremely cold systems, notably with superfluid helium, cooled to below -270.98 °C, close to absolute zero. In this state, helium defies gravity, passes through walls, and circulates without resistance.
But this time, it is light itself that has been transformed into a supersolid. A world first.
How did they do it?
The researchers used a laser that they projected onto an extremely thin semiconductor structure, composed of gallium arsenide (GaAs) and aluminum. This configuration makes it possible to trap photons in an optical cavity while forcing them to interact with electrons.
The result? The formation of polaritons, hybrid quasi-particles arising from the coupling between a photon (light) and an electronic excitation (matter).
Under certain specific conditions, these polaritons begin to organize themselves into a regular pattern, like atoms in a crystal, while moving without resistance. Light becomes a supersolid.
Why is it revolutionary?
This supersolid of light constitutes a fundamental advance in quantum physics, and above all, no extreme cryogenic cooling was required. This clears the way for a more practical exploitation of these phenomena, notably for:
- Advanced optics: ultra-precise manipulation of light.
- Quantum technologies: quantum memories, photonic circuits, and so on.
- Quantum computing: new computing architectures based on polaritons.
We may even dream, in the long run, of more futuristic applications such as systems for teleporting information, ultra-fast photonic computers, or why not… a lightsaber?
Toward a new technological paradigm
This kind of discovery shows us just how far we are still only skimming the potential of quantum physics. The ability to structure light, to make it tangible without losing its wave properties, could radically change the way we conceive the technologies of tomorrow.
We are entering an era in which light becomes programmable, architecturable, quantifiable, and usable as never before.
Conclusion
Supersolid light is no longer a science-fiction fantasy. It is a scientific reality. And this is only the beginning.
The work of these Italian researchers brings us a little closer to a future in which matter and light become one, in which the limits of classical physics fade away, and in which the impossible becomes possible.