JILA atomic clock sets new world records

January 23, 2014 •

Feeling out of synch? The world’s most precise clock is now located on the CU-Boulder campus.

In a laboratory at JILA—a joint institute of CU-Boulder and the National Institute of Standards and Technology—researchers have developed a new strontium atomic clock that has set world records for both precision and stability. It “ticks” 430 trillion times per second.   

The JILA strontium lattice clock is about 50 percent more precise than the record holder of the past few years, NIST’s quantum logic clock. The new clock is so precise it would neither gain nor lose one second in about 5 billion years, if it could operate that long. This time period is longer than the age of the Earth, an estimated 4.5 billion years old.

The strontium clock’s stability—the extent to which each tick matches the duration of every other tick—is about the same as NIST’s ytterbium atomic clock, unveiled in August 2013.

The new clock was announced Jan. 22 in the online edition of Nature.

“We already have plans to push the performance even more,” said group leader Jun Ye, an adjoint professor of physics and a NIST/JILA Fellow. “So in this sense, even this new Nature paper represents only a ‘mid-term’ report. You can expect more new breakthroughs in our clocks in the next 5 to 10 years.”

In JILA’s world-leading clock, a few thousand atoms of strontium are held in a column of about 100 pancake-shaped traps called an optical lattice formed by intense laser light. JILA scientists detect strontium’s “ticks” by bathing the atoms in very stable red laser light at the exact frequency that prompts the switch between energy levels.

Recent technical advances enabling the strontium clock’s record performance include the development of ultrastable lasers and precise measurements of key effects—atom collisions and environmental heating—that cause tiny changes in the clock’s ticking rate.

Co-authors on the research paper were B.J. Bloom, T.L. Nicholson, J.R. Williams, S.L. Campbell, M. Bishof, X. Zhang, W. Zhang and S.L. Bromley.

The research is supported by NIST, the Defense Advanced Research Projects Agency and the National Science Foundation.

Homepage atomic clock image credit: Ye group and Brad Baxley/JILA. Above photo of Jun Ye by Patrick Campbell/University of Colorado

Read the full news release.