Entanglement on an optical atomic-clock transition.

  title={Entanglement on an optical atomic-clock transition.},
  author={Edwin Pedrozo-Pe{\~n}afiel and Simone Colombo and Chi Shu and Albert F. Adiyatullin and Zeyang Li and Enrique Mendez and Boris Braverman and Akio Kawasaki and Daisuke Akamatsu and Yanhong Xiao and Vladan Vuleti{\'c}},
  volume={588 7838},
State-of-the-art atomic clocks are based on the precise detection of the energy difference between two atomic levels, which is measured in terms of the quantum phase accumulated over a given time interval1-4. The stability of optical-lattice clocks (OLCs) is limited both by the interrupted interrogation of the atomic system by the local-oscillator laser (Dick noise5) and by the standard quantum limit (SQL) that arises from the quantum noise associated with discrete measurement outcomes… 
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