Shrinking Atomic Clocks

Abstract

Physics Atomic clocks housed in national laboratories around the world provide a precise time signal on which our present high-technology lives depend. Precise synchronization allows for colossal amounts of data to be reliably transferred around networks of optic fibers at ever-increasing rates, as well as providing accurate navigation systems. With increasing demand for mobile devices, there is a requirement for these atom-based time pieces to shrink. Present chip-scale atomic-clock (CSAC) devices based on alkali atoms in a buffer gas are lightweight (<50 g) and consume little power (<150 mW) but tend to show frequency drift over time that requires frequent recalibration. Clocks based on trapped single atoms or ions should be more stable because the atoms are vacuum-packed and do not interact. However, these tend to be relatively large and power-hungry. Jau et al. have developed a miniature atomic clock based on trapped Yb ions that has size and power requirements similar to those of existing CSAC technology but also offers to match the long-term stability expected of the much larger trapping systems. Appl. Phys. Lett. 101 , 253518 (2012).