Time crystal

Crystals form repeating patterns that are the same in some directions but not all. In other words, it's not symmetrical. This characteristic of crystals' is surprising given that the law of physics that govern their formation is the same in all direction.  The phenomenon that the law of physics is symmetrical but crystals are not is known as symmetry breaking. The symmetry breaking in crystals is the symmetry breaking in space. Scientists are wondering that if symmetry breaking can also happen in time. In other words, can we create time crystals?

Thanks to Chris Monroe, we are able to know the answer today. The team led by Monroe found that symmetry breaking can be observed in a quantum system. Monroe set up a quantum system, with a line of yutterbium ions with spinning that interacts with each other. The interaction leads to a special kind of behavior. One of the properties of quantum particles is that they do not usually exist in specific locations. However, this can be changed under certain conditions. Scientists found that some group of particle interact in a way that makes all of the particles become localized. In other words, they are forced to stay in specific locations. The key property of these yutterbium ions is that its spin can be flipped around by laser beam. When laser beam flipped one of the particles upside down, it will interact with other particles and causes them to flipped too. In this experiment, Monroe found that the interaction happens at a rate that is twice of the original period. This would be like strike a key on piano twice a second but the sound comes out once a second. This weird quantum behavior, the symmetry breaking of time is the confirmation that this result is a time crystal. The result of this experiment not only illustrates that the symmetry of time is breakable but also shows how bizarre that quantum world is. The world of the quantum particle is strange, and that's where its beauty is. Today, we have more insight into the quantum world, but this is not the end. We sure will keep exploring and learning. So far, this result does not provide any application in science, but scientists believe that we can apply this result to the quantum computer, using it on quantum memory storage.