Scientists have managed to get photons to interact well enough with each other to effectively produce a new form of light. The new photon matter has characteristics that are distinct from those of normal light particles.
In a study published in the journal Science, Vladan Vuletic, from the Massachusetts Institute of Technology, and colleagues reported observing groups of three photons interacting and essentially sticking together to form a new kind of photonic matter.
The researchers said that the discovery of this new form of light may be used to perform complex and fast quantum computations and perhaps even pave way to the creation of real-life Star Wars lightsabers.
Different From Normal Light
The new form of light that the researchers created can be illustrated by the lightsaber used in the fictional Star Wars universe. The photons in the lightsaber beams would collide and crash into each other. Photons from two beams of normal light from flashlights, on the other hand, would pass right through each other.
In experiments, the researchers observed that when a very weak laser beam passes through a thick cloud of cold rubidium atoms, the photons come out bound together in pairs or in groups of three instead of exiting as single randomly spaced photons.
The photons are like some form of atom-size lightsaber. The results suggest some kind of interaction taking place among the light particles.
"We report the observation of traveling three-photon bound states in a quantum nonlinear medium where the interactions between photons are mediated by atomic Rydberg states," researchers reported in their study. "Photon correlation and conditional phase measurements reveal the distinct bunching and phase features associated with three-photon and two-photon bound states."
More Sluggish Than Normal Light Particles
Normal photons also do not have mass and travel at a speed of 300,000 kilometers per second, but the researchers found that the bound photons acquired some mass, equivalent to a fraction of that of an electron's. They are also relatively sluggish and travel 100,000 times slower than the speed of light.
Potential Applications In Quantum Computing
As photons have been shown to indeed attract or entangle each other, the researchers said that they can be harnessed to perform quantum computations.
"If photons can influence one another, then if you can entangle these photons, and we've done that, you can use them to distribute quantum information in an interesting and useful way," Vuletic said.