Physicists have taken a step closer to building objects out of pure light similar to the fictional lightsaber depicted in Star Wars.
A team of researchers from the University of Maryland and U.S. National Institute of Standards and Technology (NIST) found a means to bind light particles together to form a "two-atom molecule."
The researchers pointed out that while this is not a molecule per se, it has a similar kind of structure and is characterized by a distinct and strange type of force.
Alexey Gorshkov, from the University of Maryland, explained that they are learning how to build complex states of light that can be used to build more complex objects.
Gorshkov said that their work, which will be published in the Physical Review Letters, marks the first time that it was shown how to bind two photons that are a finite distance apart.
A photon is an elementary particle that represents a quantum of light and other forms of electromagnetic radiation. The arrangement is similar to two hydrogen atoms sitting next to each other in a molecule of hydrogen.
By tweaking some of the parameters of the binding process, the researchers have shown that photons are capable of traveling side by side with a specific distance from each other hinting that weightless particles of light can be bound into a sort of molecule with a special kind of force.
"We show that two photons coupled to Rydberg states via electromagnetically induced transparency can interact via an effective Coulomb potential," the researchers wrote. "This interaction gives rise to a continuum of two-body bound states. "
Given that many modern technologies are based on light, the researchers said that many of these would be improved once it becomes possible to engineer interactions between photons.
The ability to bind and entangle photons, for instance, could make it possible for computers to use photons as processors of information, which is currently done by electronic switches in the computer. Such technology could lead to substantial energy reduction since energy losses could be reduced if the transport and processing of data is directly done by the photons.
"Light is the fastest thing you can use to transmit information," said Rajesh Menon, from the University of Utah, who is working on a silicon chip for light-based computers. "But that information has to be converted to electrons when it comes into your laptop. In that conversion, you're slowing things down. The vision is to do everything in light."