Time crystals – suggested by physicist Frank Wilzek ​​in 2012 – have long been believed by scientists to be non-existent. However, Crystal was first created in 2016. Today, one team claims to have succeeded in connecting two time crystals into a single system. This advance brings us one step closer to the practical application of this strange phase of matter.

A time crystal It is a macroscopic quantum system in periodic motion at its geospatial (lowest energy level). As for concrete, it is a group of particles arranged in a repetitive pattern like a classic crystal, but it moves and returns to its original state from time to time like an oscillator. The arrangement of the standard crystals is repeated only in space, while that of the time crystals is repeated over time.

Because they can move indefinitely from one state to another without the input of energy, these crystals break the second law of thermodynamics, one of the most important laws of physics. Increase in entropy. At constant flow, these crystals remain constant. Because of this long-term stability and stability, they can be very useful in quantum computing.

Two-headed system with magnons

Two years ago, the same research team first witnessed A.J. Reaction between two time crystals. Not only do they interact with each other, but no one has ever observed two time crystals in the same system. In a new experiment, this time they succeeded in combining two temporary crystals made of semiconductors called “magnons” to form a two-level macroscopic system. However, such a system is an integral part of a quantum computer.

⁇ Although time crystals did not exist at first, putting two of them together works wonders. And we know that they are also present at room temperature », Samuli and AttiHe is a researcher in the Department of Physics at the University of Lancaster and is the lead author of a paper describing the experiment.

Magnons are not actually particles, but modes of collective excitation of the spin Electrons, Also known as “spin waves” – like a wave propagating through a network of spins. These magnesium was created by cooling helium-3, a rare isotope of helium. Neutron – One tenth of a degree from absolute zero (0.0001 K or -273.15 C). At this temperature, helium 3 has several phases, including two superfluids (A and B).

The researchers created two time crystals, spatially differentiated into Bose-Einstein condensates, each containing 10.¹² Magnons, in the superfluid B phase. In this system, in the absence of a driving force, the observable life of the time crystal can be extended up to a thousand seconds (109 motion periods). “, They make clear in their article.

Time crystals that can act as quits

As a reminder, the Bose-Einstein condensate is a state of matter that contains particles (bosons), at the lowest possible temperature, the lowest energy quantum state (basic state) that gives all specific properties. Atoms move very slowly and approach each other until they overlap; This creates a kind of high density “cloud of atoms” that acts as a single wave of matter.

When the two time crystals came into contact, they exchanged magnets. This exchange later modified the oscillation of each of them, creating a unified system consisting of two distinct states. It represents an important breakthrough for all technologies that rely on quantum physics. Of course, any quantum system can be defined by several conditions at the same time, and only one of these conditions can be determined by measurement – the system is in a single quantum state, but each measurement can give different results relative to its probability.

This combination of two temporal crystals opens new avenues for the development of quantum computers. Especially since another team of researchers recently proved that time crystals Can be created at room temperatureIn a system not isolated from its ambient environment.

However, there is still a lot of research to be done before these strange crystals can one day be used as cubits. In particular, the team must find a way to interact with the temporary crystals without the use of superfluids and to control these interactions more closely.

Source: S. Autti et al., Nature Communications