The Daily Mail reports:
A team of physicists were messing around with photons when they managed to get the particles to stick together and form a molecule.
The molecule behaves, they claim, just like a lightsaber by moving the light particles around in a solid mass and is unlike any matter seen before.
The discovery, reported in Nature, was made by Harvard physics professor Mikhail Lukin and MIT physics professor Vladan Vuletic after they blasted photons through a cloud of rubidium atoms.
As the photons enter the cloud of cold atoms, Lukin said, its energy excites atoms along its path, causing the photon to slow dramatically.
... When they sent more than one photon simultaneously, they noticed that the particles clumped together to form a molecule.The researchers believe that it may have applications in quantum computing and optical routers. Also:
"Lukin also suggested that the system might one day even be used to create complex three-dimensional structures -- such as crystals -- wholly out of light.
‘What it will be useful for we don't know yet, 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,’ he said.