Time Crystals Made of Light Could Soon Escape the Lab

Scientists are similar to detectives in that they sift through evidence in search of clues. A diamond necklace or a piece of table salt is just a bunch of atoms arranged in a repeating pattern. A sleuth can deduce where all the others should be by looking only at a few of the crystal's patterned atoms.

If that pattern was spread across time rather than space, what would it look like? The basis of quantum systems that exhibit crystal-like repetitive behavior is a counterintuitive concept. Frank Wilczek, a physicist at the Massachusetts Institute of Technology, was the first to theorize their existence. After years of hard work, experimentalists were able to engineer one into existence in 2021. A team of physicists led by engineer Hossein Taheri of the University of California, Riverside, have made a time crystal out of light. Their work, published in Nature Communications in February, could help time crystals transform from delicate experimental curiosities into more robust components of practical devices.