Researchers from Princeton University in a quest to answer the fundamental questions about physics of matter have started crystallizing light i.e. they are not using crystal as light but are transforming light into crystal. This is part of an effort to develop exotic materials such as room-temperature superconductors. For this, they have locked photons together, which is the basic element of light.
The team is looking to create a device that can simulate the behaviour of subatomic particles. Such a tool will help in answering questions related to atoms and molecules where modern computers fail. This is because computers operate under the rules of classical mechanics, which is a system that describes everyday world - containing things like bowling balls and planets. On the other hand the world of atoms and photons obey the rules of quantum mechanics, which includes strange and counterintuitive features. One of these odd properties is called "entanglement" in which multiple particles become linked and can affect each other over long distances.
Researchers as part of the project created a structure made of superconducting materials that contains 100 billion atoms engineered to act as a single "artificial atom". They placed the artificial atom close to a superconducting wire containing photons. By the rules of quantum mechanics, the photons on the wire inherit some of the properties of artificial atom. Generally photons do not interact with each other, but in this case researchers were able to create new behaviour in which photons interacted in some ways like particles. These interactions led to a completely new collective behaviour for light, akin to the phases of matter, like liquids and crystals, studied in condensed matter physics.
Researchers plan to expand the device and the number of interactions by increasing the structure’s ability to simulate more complex systems.