The Kolkowitz Lab at the University of California, Berkeley is using its atomic clock for research beyond keeping global time. While most of the fewer than 500 atomic clocks worldwide are located in standards institutes and serve to maintain official time, the UC Berkeley team is focused on exploring fundamental physics.
Professor Shimon Kolkowitz explained in a recent “101 in 101” video that their experiment aims to “test fundamental physics, to search for new physics, and to test relativity.” He described how his initial struggle with quantum physics during university eventually led him into a field now marking its centennial. As Herst Chair in Physics, Kolkowitz leads a group investigating new physical laws by measuring oscillations of ultra-cold strontium atoms with an optical lattice atomic clock.
Inside their vacuum chamber, these atoms reach temperatures just above absolute zero—a millionth of a degree—making it one of the coldest known environments on Earth. The setup allows researchers to manipulate and trap atoms precisely and create multiple clocks for highly accurate measurements.
Kolkowitz noted that atomic clocks have practical impacts: “The GPS network is just a bunch of satellites with very precise atomic clocks in them,” he said. “And your phone collects the signals from all of those clocks and triangulates them to figure out exactly where you are on the surface of the Earth.”
He also highlighted how advances in quantum physics and relativity reveal subtle effects such as differences in aging between a person’s head and feet due to gravity. “These clocks are so precise that they can detect the subtle changes in the passage of time due to relativity,” Kolkowitz explained.
Precision from these devices is essential not only for science but also for commerce and defense. The lab continues efforts to improve measurement accuracy even further.
Atomic clocks have existed since their first demonstration in the late 1950s but remain central to modern research. Kolkowitz credited past scientists at UC Berkeley: “This very complicated experiment is the culmination of a century or more of work into understanding atoms and how to manipulate them.” He mentioned Professor Emeritus John Clarke, who recently received the Nobel Prize in Physics for his work on quantum tunneling at Berkeley alongside Michel Devoret and John Martinis.
“It was so exciting for John Clarke to win the Nobel Prize; the research he did was so foundational for quantum science,” said Kolkowitz. “I don’t believe that their primary intention was to one day be able to build a quantum computer. And similarly with clocks like this, we’re doing basic research with the hope that people will build on the work that we do and develop entirely new technologies, and also to give us more insights into the universe around us.”
Further information about UC Berkeley faculty’s work can be found through their “101 in 101” video series.
