Harvard physicists have created a new form of matter – dubbed a time crystal – which could offer important insights into the mysterious behavior of quantum systems.
Traditionally speaking, crystals – like salt, sugar or even diamonds – are simply periodic arrangements of atoms in a three-dimensional lattice.
Time crystals, on the other hand, take that notion of periodically-arranged atoms and add a fourth dimension, suggesting that – under certain conditions – the atoms that some materials can exhibit periodic structure across time.
Led by Professors of Physics Mikhail Lukin and Eugene Demler, a team consisting of post-doctoral fellows Renate Landig and Georg Kucsko, Junior Fellow Vedika Khemani, and Physics Department graduate students Soonwon Choi, Joonhee Choi and Hengyun Zhou built a quantum system using a small piece of diamond embedded with millions of atomic-scale impurities known as nitrogen-vacancy (NV) centers. They then used microwave pulses to “kick” the system out of equilibrium, causing the NV center’s spins to flip at precisely-timed intervals – one of the key markers of a time crystal. The work is described in a paper published in Nature in March.