Technology
Scientists present the world's first nuclear clock
For the first time, scientists have managed to switch the nucleus of a thorium atom from one state to another using a laser, an effect that can be used for high-precision measurements and has enabled the creation of the world's first nuclear clock.
The study, led by professor Thorsten Schumm, from the Technical University of Vienna, was published on Wednesday (4), in the journal Nature.
Every clock needs something to act as a timer — like the regular movement of the pendulum in a grandfather clock. Today's high-precision watches often use the oscillation of electromagnetic waves from a laser beam, but even the frequency of a laser can change slightly over time and need to be adjusted.
“That's why, in addition to the laser, you need a quantum system that reacts extremely selectively to a very specific laser frequency,” explained Schumm.
Atomic clocks use cesium or strontium atoms, for example, so that if the laser frequency changes, the atoms are no longer excited efficiently and the laser can be readjusted.
If the nucleus of an atom could be used in this same way, the clock would be even more accurate, according to scientists' predictions. Atomic nuclei are much smaller than atoms and, therefore, react less to external disturbances.
Although the world's first nuclear clock has not yet surpassed the precision of existing atomic clocks, Schumm expects it to do so within the next two to three years.
“Our goal was to develop a new technology. Once it is there, the increase in quality comes naturally, this has always been the case,” he explained. “The first cars were no faster than carriages. It was all about introducing a new concept. And that is exactly what we have now achieved with the nuclear clock.”