A multi-set atomic clock improved using quantum computing tools

Atomic clocks are a class of clocks that exploit the resonant frequencies of atoms to tell time with great precision. Although these clocks have become more advanced and accurate over the years, existing versions may not make the best use of the resources they rely on to keep time.

Researchers at the California Institute of Technology recently explored the possibility of using quantum computing techniques to further improve the performance of atomic clocks. Their article, published in Natural physicsintroduces a new scheme that allows the simultaneous use of multiple atomic clocks to keep time even more precisely.

“Atomic clocks are several decades old, but their performance improves every year,” Adam Shaw, co-author of the paper, told Phys.org.

“At the same time, in recent years, the atomic physics community has seen a strong push toward the development of so-called quantum computers, devices that control the quantum states of individual atoms to perform calculations beyond the capabilities of a normal computer. Clocks and computers are apparently very different, but in recent years people have realized that they can be very synergistic.”

The main goal of the recent study by Shaw and colleagues was to use some of the tools that underpin the operation of quantum computers to improve atomic clocks. To do this, the researchers experimentally carried out a 10-year-old theoretical proposal, which involves the simultaneous use of several clocks to keep time better than a single clock, ensuring that each of them registers the passage time at different paces.

“The idea is basically the same as having multiple hands on a watch: an hour hand to track longer time changes and a minute hand to more accurately track shorter time changes,” Shaw explained. “What we have done is essentially built such a multi-handed clock at the atomic scale. To do this, we demonstrate a new way to control the electronic state of individual atoms with very high fidelity by changing their positions in a laser beam.”

The researchers used the proposed technique to control individual atoms in atomic clocks. Specifically, they ensured that each atom actually experiences a slower or faster passage of time, depending on its dynamic position relative to the applied laser beam.

“The world’s most precise current clocks work by measuring the passage of time with a large set of atoms, but we demonstrate that individual control could lead to better performance,” Shaw said. “More broadly, our work shows the power of combining the capabilities of quantum computers and quantum sensors, a union that many other groups are working to achieve and improve.”

The initial results collected by Shaw and his colleagues are very encouraging and highlight the potential of quantum computing techniques in metrology research. In the future, this study could inspire the development of other programmable optical quantum clocks with even better performance.

A few months after the team pre-published their paper, another research group led by Shimon Kolkowitz at Berkeley published a paper attempting to make a similar multi-hand clock on PRX in Physical examination. Their multi-hand clock was created using a different technique, but it also highlights the benefits of relying on more than one atomic clock at a time.

“In our recent paper, we controlled several individual atomic clocks, but the clocks themselves were relatively simple: just single atoms,” Shaw added.

“We are currently working to use quantum entanglement between individual atoms within each clock so that each ‘hand’ of our atomic watch becomes more precise. This should improve the performance of the clock and would be a true hybrid of a quantum computer and an atomic clock.”

© 2024 Science X Network