Princeton Researchers Transform Light into Solid Crystal
Princeton researchers have discovered a method for crystallizing light, which could be a breakthrough in the fundamental study of matter.
"It's something that we have never seen before," said Andrew Houck, an associate professor of electrical engineering. "This is a new behavior for light."
In order to "freeze" the light into crystal, the research team bound together photons and "locked" them in order to make light mimic the properties of a solid, using a machine that mimics the "spooky" entanglement behavior of subatomic particles. Under normal circumstances, photons don't interact with each other at all, but the researchers were able to induce interaction in which the photons behaved like particles rather than waves. "Here we set up a situation where light effectively behaves like a particle in the sense that two photons can interact very strongly," said Hakan Türeci, an assistant professor of electrical engineering. "In one mode of operation, light sloshes back and forth like a liquid; in the other, it freezes."
The machine consists of a structure composed of superconducting materials that cause 100 billion atoms to behave like one artificial atom. When they placed the "artificial atom" next to a superconducting wire that contained photons, the photons began to act like solid material. "We have used this blending together of the photons and the atom to artificially devise strong interactions among the photons," said Darius Sadri, a postdoctoral researcher. "These interactions then lead to completely new collective behavior for light – akin to the phases of matter, like liquids and crystals, studied in condensed matter physics."
On the left, the photons flow between superconductors like waves until they become frozen in place, on the right:
[Credit: Princeton University]
The device, which significantly operates according to quantum mechanics rather than classical physics, could potentially help researchers observe previously unobservable states, such as superfluidity. The researchers have long theorized that a machine that operates according to quantum mechanics could solve previously unsolvable problems, such as the creation of a room temperature superconductor.
"We are interested in exploring – and ultimately controlling and directing – the flow of energy at the atomic level," said Türeci. "The goal is to better understand current materials and processes and to evaluate materials that we cannot yet create."