Ultra-stable optical clock with two cold-atom ensembles

Understand

Atomic clocks based on optical transitions are the most stable, and therefore precise, timekeepers available.

• These clocks operate by alternating intervals of atomic interrogation with dead time required for quantum state preparation and readout.
• This non-continuous interrogation of the atom system results in the Dick effect, an aliasing of frequency noise of the laser interrogating the atomic transition.
• Despite recent advances in optical clock stability achieved by improving laser coherence, the Dick effect has continually limited optical clock performance.