A group at TU Dortmund University recently managed to produce an extremely durable time crystal that lasts millions of times longer than previous experiments had shown. With this, they confirmed an extremely interesting phenomenon that Nobel laureate Frank Wilczek proposed about ten years ago and has already become the subject of science fiction movies. Results published on: Nature Physical.

Crystals, or more precisely crystals in space, are periodic arrangements of atoms on large scales. This arrangement gives crystals a fascinating appearance with smooth surfaces like those of gemstones.

Because physics often treats space and time on the same level, for example in special relativity, physicist Frank Wilczek of the Massachusetts Institute of Technology (MIT) and Nobel laureate in physics proposed in 2012 that in addition to crystals in space, there must be crystals in and over time.

For this to be the case, he said, one of its physical properties must begin to spontaneously change periodically over time, even if the system does not experience corresponding periodic disturbances. The possibility of such time crystals has been the subject of controversial scientific debate for several years, but they quickly found their way into theaters: for example, a time crystal played a central role in Marvel Studios’ Avengers: Endgame (2019).

Since 2017, scientists have managed to demonstrate a potential time crystal several times. However, these were systems that, contrary to Wilczek’s original idea, were temporarily excited with a certain periodicity, but then responded with a period twice as long.

Although the excitation is time-independent, i.e. constant, it was demonstrated only in 2022 in a crystal Bose-Einstein condensate that behaves periodically in time. But the crystal only lived for a few milliseconds.

Dr. Dortmund physicists led by Alex Greilich have developed a special indium gallium arsenide crystal in which nuclear spins act as a reservoir for the time crystal. The crystal is continuously illuminated, so that polarization of the nuclear spin occurs due to interaction with the spins of the electrons. And it is this nuclear spin polarization that spontaneously produces oscillations equivalent to a time crystal.

Current experiments indicate that the crystal has a lifetime of at least 40 minutes; This is 10 million times longer than has been proven to date, and potentially much longer.

It is possible to change the period of the crystal within wide limits by systematically changing the experimental conditions. However, movement is also possible in the region where the crystal “melts”, that is, loses its periodicity. These regions are also interesting because they exhibit chaotic behavior that can persist for long periods of time. For the first time, scientists can use theoretical tools to analyze the chaotic behavior of such systems.