A group of scientists has announced the creation of one of the most powerful atomic clocks ever built.
The gadget is supposed to be so precise in measuring the time that it will only lose one second every 300 billion years, enabling more accurate measurements of gravitational waves, dark matter, and other physical phenomena. A paper based on the UW-Madison research was published in the journal Nature.
“Optical lattice clocks are already the best clocks in the world, and here we get this level of performance that no one has seen before,” Shimon Kolkowitz, a University of Wisconsin-Madison physics professor and senior author of the study, said in a statement.
“We’re working to both improve their performance and to develop emerging applications that are enabled by this improved performance.”
Atomic clocks, in general, are clocks that follow the resonances of atom frequencies, most often cesium or rubidium atoms. This method enables such clocks to measure time with high precision. NASA’s Deep Space Atomic Clock is an example of a space-based experiment in which the technology was tested in orbit for two years.
Atomic clocks operate by monitoring electron energy levels.
“When an electron changes energy levels, it absorbs or emits light with a frequency that is identical for all atoms of a particular element,” the university explained.
“Optical atomic clocks keep time by using a laser that is tuned to precisely match this frequency, and they require some of the world’s most sophisticated lasers to keep accurate time.”
In the new study, strontium atoms were sorted into a line in a single vacuum chamber using a multiplexed clock. The team utilized a “relatively lousy laser,” as Kolkowitz put it, yet it nevertheless managed to achieve near-world-record precision in measurement.
If they just focused the laser on one clock, it only stimulated electrons in the same number of atoms for one-tenth of a second. However, with two clocks running simultaneously, the atoms remained excited for 26 seconds.
NASA’s Deep Space Atomic Clock, shown here in an artist’s rendering, will put new technologies for deep-space navigation to the test.
“Normally, our laser would limit the performance of these clocks,” Kolkowitz said. “But because the clocks are in the same environment and experience the exact same laser light, the effect of the laser drops out completely.”
The scientists then tried to detect clock discrepancies carefully because two groups of atoms in slightly different settings may “tick” at different speeds due to magnetic fields or gravity variations. The scientists repeated the experiment 1,000 times to determine the difference, discovering more precision in that measurement with time.
The researchers eventually discovered a difference in the ticking rate of two atomic clocks “that would correspond to them disagreeing with each other by only one second every 300 billion years — a measurement of precision timekeeping that sets a world record for two spatially separated clocks” according to the university.