The findings are significant in that these molecules are a totally new form of matter.
The research occurred at the Harvard-MIT Center for Ultracold Atoms, led by Mikhail Lukin, a Harvard professor of physics and Vladan Vuletic, an MIT physics professor. The results are described in the journal Nature.
The molecules the team created, formed by the fusion of photons, challenges previous assumptions that photons, particles of light, are without mass. Photon molecules behave not like lasers, but more like lightsabers.
To create them, the researchers pumped rubidium atoms into a vacuum chamber, used lasers to cool them to just above absolute zero, then used weak laser pulses to fire photons into the atom clouds.
The photon then excites other atoms with its energy as it passes through the cloud, slowing the photon down. When the team fired two photons into the cloud, the result was one new photon molecule.
The reason the photons are able to form a molecule is due to what is called the Rydberg blockade, a scientific principle that states that when an atom is excited, nearby atoms can’t be excited to the same degree. This means that when two photons enter the atomic cloud, one has to move forward before the other can progress, resulting in a push-and-pull motion that eventually leads to the two photons getting together.
The researchers unfortunately aren’t planning to mass-produce lightsabers, unfortunately. They hope to use the technology to build better quantum computers.
