Physicists at the University of Toronto, Canada, have developed the world’s first cryogenic single-ion trap for regulating the accuracy of an optical atomic clock. This marks a significant advance in atomic timekeeping, potentially improving precision by up to a factor of 100 compared to current systems.
The system was created by Professor Amar Vutha and PhD student Takahiro Tow from the Department of Physics, Faculty of Arts & Science. Their work builds on existing atomic clock technology, which uses the oscillations of electromagnetic fields in lasers synchronized with atoms to maintain time. In this case, a single strontium ion is trapped using electromagnetic fields and synchronized with an optical laser.
A key innovation in their design is the use of cryogenic temperatures. By cooling the strontium atom to below five Kelvin (−268.15°C), the system eliminates infrared radiation — or heat — from surrounding materials, which can otherwise disturb the atom and reduce the clock’s accuracy.
The development forms part of a broader shift away from cesium-based microwave clocks toward more precise optical systems. According to Vutha, improved timekeeping strengthens the foundation of physical measurements, including electrical standards like current and voltage, and enables fundamental research such as testing the constancy of physical constants.
“So, atomic clocks can be used to check whether these fundamental constants are actually constant,” said Vutha. “There’s just no other way of doing these kinds of experiments than with atomic clocks.”
