NIST logo

NIST Unveils Chip-Scale Atomic Clock

For Immediate Release: August 27, 2004

Bookmark and Share

Contact: Laura Ost




“The real power of our technique is that we’re able to run the clock on so little electrical power that it could be battery operated and that it’s small enough to be easily incorporated into a cell phone or some other kind of handheld device,” says physicist John Kitching, principal investigator for the project. “And nothing else like it even comes close as far as being mass producible.”

The mini-clock is comparable in size and long-term stability to temperature-compensated quartz crystal oscillators, currently used in portable devices. NIST scientists expect to improve the clock’s long-term stability and reduce its power consumption to the point where the device could substantially improve the performance of many commercial and military systems that require precision time keeping.

The chip-scale clock is the latest advance in time keeping at NIST, which for decades has been a world leader in the development of new technologies for measuring time and frequency. Atomic clocks long have provided the most accurate realizations of both of these quantities but also have traditionally been large—up to two meters in height—as well as power-hungry and expensive to build.


The chip-scale clock is less accurate than larger atomic clocks such as fountain clocks. However, the clock’s small size, low power dissipation and potentially low cost make it ideal for a variety of commercial and military applications. Compared to quartz crystal oscillators, the most precise time and frequency references of equivalent size and power, chip-scale atomic clocks potentially offer a 1,000-fold improvement in long-term timing precision.

Chip-scale atomic clocks have many potential uses. In wireless communications devices, these clocks could improve network synchronization and channel selection to enhance security and anti-jamming capabilities. In Global Positioning System (GPS) receivers, small clocks could improve the precision of satellite-based navigation systems such as those used in commercial and military vehicles and emergency response networks. In addition, as atomic clocks get smaller and cheaper and use less power, they could replace quartz crystal oscillators in many common products such as computers, offering several orders of magnitude better time keeping.

The integrated design described in the paper also could be modified to make millimeter-scale magnetic field sensors based on atoms as well as a variety of other miniaturized spectroscopic tools and devices.

The work was supported by NIST and the Defense Advanced Research Projects Agency (DARPA).

For more information on the chip-scale clock, go to


- 30 -


Kitching chip scale clock

NIST physicist John Kitching displays the heart of the world's smallest atomic clock. This "physics package" is about the size of a grain of rice.© Geoffrey Wheeler

To receive a high resolution version of these images contact Gail Porter,, (301) 975-3392.


NIST Photo

Click on the image to get the high resolution version.