The two time crystals were created within superfluid helium-3 that was cooled in this rotating ultra-low temperature cryostat at Aalto University. Photo: Aalto University/Mikko Raskinen.For the first time ever, scientists have witnessed the interaction of a new phase of matter known as ‘time crystals’.
Their discovery, reported in a paper in Nature Materials, may lead to applications in quantum information processing. This is because time crystals automatically remain intact, or coherent, over varying conditions, and protecting coherence is the main challenge hindering the development of powerful quantum computers.
"Controlling the interaction of two time crystals is a major achievement," said lead author Samuli Autti from Lancaster University in the UK. "Before this, nobody had observed two time crystals in the same system, let alone seen them interact.
"Controlled interactions are the number one item on the wish list of anyone looking to harness a time crystal for practical applications, such as quantum information processing."
Time crystals differ from the standard crystals that make up metals or rocks, which are composed of atoms arranged in a regularly repeating pattern in space. First theorised in 2012 by Nobel Laureate Frank Wilczek and identified in 2016, time crystals exhibit the bizarre property of being in constant, repeating motion, despite no external input. Their atoms are constantly oscillating, spinning or moving first in one direction and then the other, producing a regularly repeating pattern in time.
An international team of researchers from Lancaster University, Royal Holloway London, Yale University and Aalto University in Helsinki, Finland, observed time crystals in helium-3, which is a rare isotope of helium with one missing neutron. The experiment was carried out at Aalto University.
First, the researchers cooled the superfluid helium-3 to within one ten thousandth of a degree of absolute zero (0.0001K or -273.15°C). Then they created two time crystals within the superfluid and allowed them to touch. In this way, they were able to observe the two time crystals interacting and exchanging constituent particles, which flowed from one time crystal to the other and back – a phenomenon known as the Josephson effect.
Time crystals have great potential for practical applications. They could be used to improve atomic clocks, complex timepieces that keep the most accurate time that can possibly be achieved. They could also improve technology such as gyroscopes and systems that rely on atomic clocks, such as GPS.
This story is adapted from material from Lancaster University, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.