Next-gen nuclear clocks that are 10x more accurate developed using lasers

Not too long ago scientists made a breakthrough in devising nuclear clocks that may even be more precise thus than current clocks (optical clacks) and are likely less sensitive to disturbances too.

Now physicists from RIKEN Quantum Metrology Laboratory, a national scientific research institute in Japan have made another breakthrough in devising nuclear clocks using lasers.

These nuclear clocks were innovated by measuring the lifetimes of thorium-229 nuclei. Thorium-229 ions, specifically those that are triply charged (229Th3+), have been successfully trapped and their decay lifetime was accurately measured using lasers.

10x more accurate than optical atomic clocks

In contrast to top-notch optical atomic clocks which require over twice the current age of the Universe to deviate by one second for an unimpeachable level of precision, nuclear clocks may scientists unravel dark matter.

For the next generation of timekeepers, nuclear clocks are likely capable of becoming 10 times more precise than optical atomic clocks.

This is because the nucleus in nuclear clocks is less sensitive to external electromagnetic fields and temperature fluctuations compared to electrons, according to RIKEN .

In their ambition to develop more accurate next-generation nuclear clocks, scientists used thorium-229 because its nucleus is less sensitive to external factors, unlike the electrons in optical atomic clocks.

This increased accuracy could help in discovering new physics phenomena, such as dark matter .

Experts employed a technique involving lasers to devise and trap triply charged thorium-229 ions (229Th3+), which are then measured for their decay lifetime.

According to the statement, one promising approach for realizing a nuclear clock is to trap thorium-229 ions missing three electrons (229Th3+). Such thorium ions have the advantage of being able to be cooled by lasers.

“They can also be easily detected thanks to the fluorescence they give off when illuminated by laser light,” RIKEN stated.

The thorium-229 nucleus is particularly valuable because it can be excited with a vacuum ultraviolet laser due to its exceptionally low excitation energy. By measuring the lifetime of these ions, the researchers ensure that they can be used effectively in nuclear clocks.

Probing nuclear clock with laser

However, scientists say that it’s important to be mindful of certain parameters such as the nuclear clock’s decay lifetime need to be measured accurately.

To tackle this issue, the team used triply charged thorium-229 isomer ions from uranium. It was then probed with a laser.

Atsushi Yamaguchi of the RIKEN Quantum Metrology Laboratory was elated to see the system come to fruition through trapping ions.

“We showed that we really can trap triply charged thorium -229 ions generated from uranium in this apparatus,” he said.

“That had never been done before, and some people had expressed doubts that our approach would work.”

Another aspect that the team was assured of was that the measured lifetime of the thorium-229 ions—about 1,400 seconds—was just right.

“If the lifetime was too long then we couldn’t measure it, and if it was too short then we couldn’t use the ions to realize a highly accurate nuclear clock,” Yamaguchi explained.

“1,400 seconds is a very nice lifetime for nuclear clock applications.”

Currently, the team of physicists is concentrating on devising a new laser to probe the nuclear clock.