In a recently published research article, researchers at Google claim that they have used a quantum processor to observe a real time crystal, this writes ZDNet. According to the researchers, time crystals are “a new phase of matter.” A new status has been theorized that has the potential to join the ranks of solids, liquids, gases and crystals.
To understand why time crystals are interesting requires knowledge of the second law of thermodynamics, which states that a system naturally tends to stay in a state called “maximum entropy.” ZDNet describes with the example that if you pour milk into a coffee cup, the milk will eventually distributed through all the coffee, instead of just floating on the surface, so that the overall system comes into equilibrium.This is because there are many more ways for the milk to spread randomly in the coffee than there are for it to be still, on a more orderly way, at the top of the cup.
This irresistible driving force against thermal equilibrium, described in the second law of thermodynamics, reflects the fact that all things tend to move towards less useful, random states. As time goes on, systems inevitably degenerate into chaos and disorder – that is, entropy.
Time crystals, on the other hand, do not get stuck in a thermal equilibrium. Instead of slowly degenerating towards randomness, they get stuck in two high-energy configurations that they switch between.
Does that sound weird? Curt von Keyserlingk, a lecturer in physics and astronomy at the University of Birmingham, has another example. Take a box in a closed system that is isolated from the rest of the universe. Fill it with a dozen coins and shake it a million times. As the coins bounce against each other, they randomly move positions that become increasingly chaotic. When you open the box, the expectation is that you will face about half of the coins with the crown up and half with the claw down. It does not matter if the experiment started with more coins with a crown or piano up or down; the system forgets the original configuration and it becomes increasingly random and chaotic when shaken.
This is where time crystals set all expectations on its head. “What constitutes a time crystal is that it remembers what it did in the beginning. It does not forget, ”says von Keyserlingk. The coins in the box system forget their original configuration, but a time crystal system does not. They defy the other laws of thermodynamics, which define all natural events.
So far, there is no direct application where time crystals can be used, but they may have a role in advancing scientific physics.