Scientists Link Two Time Crystals for the First Time

Researchers have achieved something that is simply out of a science fiction movie. For the first time, they have linked isolated groups of particles — known as time crystals — into a single, evolving system that could be incredibly useful in quantum computing. A team of physicists, working together under Lancaster University's Samuli Autti, have successfully coupled two time crystals to create a 'two-state system', also known as 'two-level system'. This can pave a new way for quantum computers that can use time crystals as qubits.

Time crystals, where considered to be practically impossible to create until they were discovered in 2016. They were first theorised by Nobel Laureate Frank Wilczek back in 2012. These time crystals were observed interacting for the first time in 2020 by the same team from University of Lancaster. However, at the time, no one would have thought about linking these crystals in such a way that they can be used as qubits from quantum computing.

Time crystals are similar to normal crystals, like metals or rocks, but carry a special property. In normal crystals, the atoms are arranged in a fixed, 3D grid structure. In time crystals, the atoms show patterns of movement in time that can't be easily explained by an external push. These oscillations – referred to as “ticking” – are locked to a regular and particular frequency.

The main reason physicists believed creating time crystals were considered impossible is because their atoms are in a perpetual motion that would seem to defy the laws of physics. However, quantum physics not only helped create time crystals, but scientists have also shown that these crystals have the potential to power useful devices.

"Everybody knows that perpetual motion machines are impossible. However, in quantum physics, perpetual motion is okay as long as we keep our eyes closed. By sneaking through this crack we can make time crystals," said physicist and lead author Samuli Autti of Lancaster University in the UK.

The time crystals were first observed using helium-3, a rare isotope of helium with one missing neutron. The team cooled superfluid helium-3 to -273.15 degrees Celsius. The researchers then created two time crystals inside the superfluid and brought them to touch. They then watched the two time crystals interacting.

The researchers have published their findings in the journal Nature Communications.