QUANTUM CLOCKS

A quantum clock is a type of atomic clock with laser cooled single ions confined together in an electromagnetic ion trap. The UV laser measures the aluminum ion vibration at an optical frequency to track time. Many of today's quantum optical lattice clocks can now operate at an uncertainty level of at least 10 to the minus 18; a real milestone for atomic timekeeping. This level of accuracy means that the clocks will gain or lose one second every 30 billion years, a period greater than the age of the Universe.