Time crystals are ‘impossible’, but they are subject to quantum physics

In a new experiment, scientists create two time crystals inside a superfluid, and bring them into contact.

Time crystals have long been thought to be impossible because their perpetual motion appears to defy the laws of physics. However, using quantum physics Scientists have not only created time crystals, but they are now also showing that they have the potential to power useful devices in the future.

Scientists have created the first two-body “time crystal” system in an experiment that appears to twist the laws of physics.

This comes after the same team recently witnessed the first interaction of a new phase of the matter.

Time crystals have long been believed to be impossible because they are made of atoms in never-ending motion. The discovery published today (June 2, 2022) in the magazine Nature Communicationsshows that not only can time crystals be created, but that they can be turned into useful devices.

Time crystals differ from standard crystals – such as minerals or rocks – which consist of atoms arranged in a regularly repeating pattern in space.

First developed in 2012 by Nobel laureate Frank Wilczek and defined in 2016, time crystals exhibit the peculiar property of being stationary, repeating motion in time despite no external input. Their atoms are constantly oscillating, spinning, or moving first in one direction, and then in the other.

The researchers cooled liquid superfluid helium-3 to nearly absolute zero (minus 273.15 degrees Celsius) inside this rotating refrigerator, twice creating crystals and keeping them within reach. Image Credit: © Aalto University / Mikko Raskinen

EPSRC Fellow Dr Samuli Ooty, lead author from the Department of Physics at Lancaster University, explained: “Everyone knows that perpetual motion machines are impossible. However, in quantum physics, perpetual motion is OK as long as we close our eyes. By slipping through this crack we can make Time crystals.

“It turns out that putting the two of them together works beautifully, even if the time crystals weren’t present in the first place. And we already know that they are also present at room temperature.”

The “two-level system” is a fundamental building block of a quantum computer. Time crystals can be used to build quantum devices that operate at room temperature.

An international team of researchers from Lancaster University, Royal Holloway London, the Landau Institute and Aalto University In Helsinki, time crystals were observed using helium-3, a rare isotope of helium with one neutron missing. The experiment was conducted at Aalto University.

They cooled superfluid helium-3 to about one ten thousandth of a degree from[{” attribute=””>absolute zero (0.0001K or -273.15°C). The researchers created two time crystals inside the superfluid, and brought them to touch. The scientists then watched the two time crystals interacting as described by quantum physics.

Reference: “Nonlinear two-level dynamics of quantum time crystals” 2 June 2022, Nature Communications.
DOI: 10.1038/s41467-022-30783-w