Throw out every idea that you had about the physical world around you and let’s try to contextualize the idea of the new form of matter; time crystals. What in the world is this new physical state and how are we actually going to utilize such a structure?
A new state of matter was proposed back in 2012 by Frank Wilczek which was disproved later on in the year by scientists when following his vision of time crystals. It wasn’t until this year that they were created; not once but twice, and using two different techniques. Scientists from the University of Maryland and Harvard University were the two that independently published their finds in the journal Nature. The group from Maryland created the crystals by levitating the element ytterbium with electromagnetics and hitting it with lasers in a vacuum. Harvard on the other hand, used a black diamond with millions of nitrogen impurities (reason behind its colour) and hit it with lasers and microwaves; both ways created time crystals. Now comes the part of explaining how this all actually works.
The 3 states of matter that we need to know about for this is solid, liquid and gas. Solids have a fixed volume and shape, liquids have a fixed volume and unfixed shape, and gases have an unfixed volume and shape. These states are in equilibrium when at rest; meaning that in a constant environment, each atom has the same level of energy. The energy levels only start to change when something around it changes. It’s when change occurs (energy is added) that theses states can actually move between phases and interact with the world around them. At an atomic level, stable or ‘ground state’ matter is a constant and repetitive arrangement of atoms that define its structure; repeating itself in space. The unusual thing about time crystals is that the structure repeats itself in time, not space.
Time crystals are a state of ‘non-equilibrium’ matter; it is a state of matter where the atoms are oscillating and changing while at ‘ground state’. Using lasers and microwaves, the spin of the atoms within the different crystals were flipped, creating an asymmetrical structure. The way in which the atoms were flipping however didn’t match the level of energy that was being added to them by either lasers or microwaves. Alternatively, they had a preferred rhythm that they followed. This preferred rhythm allow for scientists to identify the orientation of oscillating atoms at a particular point in time. To simplify this as much as possible, think about this.
I have a normal diamond and no matter where I look at it while it is at ‘ground state’, the atomic structure follows a particular lattice pattern in space. Time crystals follow the same basic idea but in time, not space. Due to the particular pattern that the atoms oscillate in, we know what orientation the atoms will be in at different points in time; even though the orientation is changing without energy being put into it. Even though all of this is incredibly amazing, there are very few real-world applications for it. Scientists are hoping that time crystals could help in increasing the complexity and stability of quantum computer functions or aid in the construction of new types of quantum clocks. Regardless, the actual creation of this theorized state opens up a whole new understanding of the world around us with some potentially unforeseeable applications.