Atomic clocks use quantum timekeeping

Summary: 

A quantum trick could provide sharper ticks for the atomic clocks of the future.

Two groups, one led by Markus Oberthaler at the University of Heidelberg in Germany, and the other by Philipp Treutlein of the AQUTE project, at the Ludwig-Maximilians University of Munich, Germany, have shown that quantum entanglement can make the measurement technique used by atomic clocks even more precise.

The full story can be read at Nature News.
Have also a look at the following AQUTE highlight.