Scientists from the University of Maryland and the University of California-Berkeley have successfully created something that was previously considered theoretically impossible.
This something is a chain of ions, which is the first incarnation of the so-called space-time crystal, a crystal whose structure consists of elements repeating not only in space but also in time. The very existence of such crystals violates some of the fundamental physical laws, which causes a number of exotic effects. For example, a clock built on the basis of such a crystal will “tick” even after the thermal death of the Universe, at the moment when all movement stops and time, according to some scientists, will simply stop.
While ordinary crystals have a crystal lattice consisting of the same alternating elements, a space-time crystal is in motion, returning to a certain form at regular intervals. At the same time, to ensure the movement of the elements of the space-time crystal and change its structure, no energy is required, drawn from an external source. The theoretical possibility of creating such crystals in 2012 was substantiated by Frank Wilczek, a physicist at the Massachusetts Institute of Technology, although most other scientists have denied and continue to deny this possibility.
The time crystal created by the scientists is a quantum ring system made up of ytterbium atoms that can rotate in two directions, up or down. Using laser light, the scientists controlled the direction of rotation of the ions in one of the halves of the circular chain. In the created quantum system, the rotation of each has an effect on neighboring ions, and such an effect has led to the fact that the "inverted" ions, having passed in most cases a full circle, return to their original state. At the same time, the time to return to the initial state is exactly twice the time spent by the ion to travel the path from the conditional beginning of the circle to the point of its "overturning".
Scientists have found that ions return to the original orientation of the direction of their rotation, always with the same speed, which does not depend on the moment in time and point in space. This, in turn, indicates that the quantum system reacts in a strictly defined way to “disturbances” in its state. And all this is very similar to the behavior of atoms in the crystal lattice of a crystal, which move from their place under some external influence.
The creation of the first sample of a space-time crystal is of great importance for physics due to the fact that the existence of such a crystal violates a fundamental physical concept, symmetry. And further research in this direction may lead to the identification of some completely new laws of physics and quantum mechanics, on the basis of which it will be possible to create technologies that can now be considered something from the category of science fiction.