Lucasfilm
"The
Normally light doesn't interact with other light - when two lasers collide, nothing happens. By cooling light and shooting it through a cloud of atoms, however, the researchers were able to get the light to interact, even binding together to create molecules. Before this finding, the state of matter was only theoretical.
They did it by supercooling a bunch of rubidium atoms in a vacuum then hitting them with two photons of light. The photons entered separately but left the cloud of atoms together, having pushed and pulled each other through the cloud and bound into one packet.
As the individual photons moved through the atoms they excited then, then took that energy back as it moves away from the atom. The energy level transferred to the atoms is at level called a Rydberg state. Two atoms can't be in the same Rydberg state, so this slows the photon down as it passed from one atom to the next.
The photon traveling behind the first has to wait for the next atom to be ready to accept its energy and reenter the Rydberg state, so it is essentially twinned with the first photon, linking the two together.
They compared this to lightsabers from the
The matter is only created at very cold temperatures, so don't expect lightsabers any time soon. The researchers aren't even sure what this new matter could be used for - they still need to study it.
"What it will be useful for we don't know yet," Lukin said. "But it's a new state of matter, so we are hopeful that new applications may emerge as we continue to investigate these photonic molecules' properties."
One potential application is in quantum computing. And Lukin even said that in the future we might be able to make 3-D structures, like crystals, out of light. The finding was published Sept. 25 in the journal Nature.