Physicists are accustomed to dealing with some of the strangest forms of matter and ideas in our known world, from uplifting superconducting materials to the mind-bending theory of time dilation. But even for physicists, time crystals are strange.
They may sound like some hidden treasure of retro science fiction TV villain, or maybe fuel for a TARDIS of Time Lord, but this unusual state of affairs is quite a fixture of our reality. Critically, scientists have observed the interaction for these crystals for the first time.
This observation takes scientists one step closer to understanding the strangeness of our world, and also has the potential to heat up ‘quantification’, making it much cheaper and more accessible.
The interaction is detailed in a study published Monday in the journal Natural materials.
What is a time crystal?
We are all familiar with the most common forms of natural matter – liquid, gas, solid, and even plasma. Time crystals, on the other hand, are a newly discovered kind of thing. This strange case was first theorized in 2012 by Nobel Prize and MIT professor Frank Wilczek and confirmed just four years ago.
Samuli Autti, a research fellow at Lancaster University and first author of the New Age Crystal Study, explains Inverse that time crystals are real a collection of particles in constant motion without an external force.
“Conceptually, a time crystal is a very simple thing: It is a substance in which the constituent particles are constant, systematically repeating motion, even in the absence of any external encouragement,” explains Autti. “This is very unusual in nature.”
He also acknowledges the phrase “time crystal” “sounds like someone adopted the name from a 1980s science-fiction show.”
How to make a time crystal – To make these time crystals, the team first cools (to just above absolute zero at almost -460 degrees Fahrenheit) a most vacuum-filled red tube with a rare helium isotope. Two copper coils were then placed around the tube and given a “kick” (aka, a radio frequency pulse was transmitted through them) to generate two clouds of constantly rotating magnetic particles. These are not something you can see with the naked eye per se, but Autti explains that these clouds create a signal that can be measured to confirm their presence and the number of particles of which they are composed.
These mysterious clouds are the time crystals.
What the team found, through these invisible signals of the time crystals, was the exchange of particles back and forth between these two clouds, which signaled that the time crystals were in contact with each other.
If this result sounds confusing, Autti says it took the research team a few years to fully understand it themselves.
“It has taken us all this time to really understand what happened in the experiment and what the correct, clear language would be to present it so that the community would understand it,” says Autti. “Ultimately, the outcome may be simple and clear, but it is only so because of a number of failed attempts and a pile of rejected ideas.”
What time crystals mean for quantum computing – Another exciting part of this discovery for researchers, besides simply observing this interaction, is that it is also an experimental confirmation of something called the AC Josephson effect, a macroscopic quantum phenomenon that has applications in the field of quantum processing.
Autti says it is difficult to know exactly where a discovery like this will take the field of physics or what its future applications may be, but some potential applications for this discovery include improved atomic clocks (which in turn improve technology would like gyroscopes and GPS) as well as quantum computing.
“In principle, today’s superconducting candidates for the components of a quantum computer are based on a Josephson junction between two superconducting metals,” explains Autti. “In essence, this is the same thing as the interaction we observed between [the] twice crystals. ”
In addition to demonstrating the time crystals of this quantum effect, Autti says that time crystals are good at intrinsically protecting their own coherence. This means that they are not easily thrown from outside stimuli – a necessary feature for sensitive quantum computers.
Perhaps most excitingly, it is potential for these time crystals to begin a new era of “hot” (as, non-absolute zero) quantum processing. Because of the similarity of these crystals to a solid state substance that condenses at room temperature, Autti and his colleagues believe that time crystals can do the same. The ability to remove super complicated and expensive quantum computer storage rooms could be a big step in making this technology more accessible and scalable.
However, Autti says there is a lot of work to be done before this reality comes to fruition:
“As far as the timeline of applications is concerned, many steps towards a more achievable practical realization are needed before one can expect applications.”
Abstract: Quantum time crystals are systems characterized by spontaneously rising periodic order in the time domain. Although originally a phase of broken time translation symmetry was but a speculation, a wide range of time crystals have been reported. However, the dynamics and interactions between such systems have not been experimentally investigated. Here, we study two adjacent quantum crystals realized by two magnon condensates in excess 3He-B. We observe an exchange of magnets between the time crystals leading to oscillations in opposite phases in their populations – a signature of the AC Josephson effect – while the defining periodic motion phase remains coherent throughout the experiment. Our results prove that time crystals follow the general dynamics of quantum mechanics and provide a basis for further investigating the fundamental properties of these phases, opening up continuous paths for possible applications in developing fields, such as processing quantum information.
