%0 Generic %1 li2021improved %A Li, Weidong %A Wu, Shuyuan %A Smerzi, Augusto %A Pezzè, Luca %D 2021 %K journalclubqo %T Improved absolute clock stability by the joint interrogation of two atomic states %U http://arxiv.org/abs/2104.14309 %X Improving the clock stability is of fundamental importance for the development of quantum-enhanced metrology. One of the main limitations arises from the randomly-fluctuating local oscillator (LO) frequency, which introduces "phase slips" for long interrogation times and hence failure of the frequency-feedback loop. Here we propose a strategy to improve the stability of atomic clocks by interrogating two out-of-phase state sharing the same LO. While standard Ramsey interrogation can only determine phases unambiguously in the interval $-\pi/2,\pi/2$, the joint interrogation allows for an extension to $-\pi,\pi$, resulting in a relaxed restriction of the Ramsey time and improvement of absolute clock stability. Theoretical predictions are supported by ab-initio numerical simulation for white and correlated LO noise. While our basic protocol uses uncorrelated atoms, we have further extended it to include spin-squeezing and further improving the scaling of clock stability with the number of atoms. Our protocol can be readily tested in current state-of-the-art experiments.

@misc{li2021improved, abstract = {Improving the clock stability is of fundamental importance for the development of quantum-enhanced metrology. One of the main limitations arises from the randomly-fluctuating local oscillator (LO) frequency, which introduces "phase slips" for long interrogation times and hence failure of the frequency-feedback loop. Here we propose a strategy to improve the stability of atomic clocks by interrogating two out-of-phase state sharing the same LO. While standard Ramsey interrogation can only determine phases unambiguously in the interval $[-\pi/2,\pi/2]$, the joint interrogation allows for an extension to $[-\pi,\pi]$, resulting in a relaxed restriction of the Ramsey time and improvement of absolute clock stability. Theoretical predictions are supported by ab-initio numerical simulation for white and correlated LO noise. While our basic protocol uses uncorrelated atoms, we have further extended it to include spin-squeezing and further improving the scaling of clock stability with the number of atoms. Our protocol can be readily tested in current state-of-the-art experiments.}, added-at = {2021-04-30T08:53:04.000+0200}, author = {Li, Weidong and Wu, Shuyuan and Smerzi, Augusto and Pezzè, Luca}, biburl = {https://www.bibsonomy.org/bibtex/2e634f86ac691b9a8de6a6b82bf67a766/klhamm}, description = {[2104.14309] Improved absolute clock stability by the joint interrogation of two atomic states}, interhash = {98ddc1cd319f62c55e984cc79e38f1c6}, intrahash = {e634f86ac691b9a8de6a6b82bf67a766}, keywords = {journalclubqo}, note = {cite arxiv:2104.14309Comment: 15 pages, 10 figures}, timestamp = {2021-04-30T08:53:04.000+0200}, title = {Improved absolute clock stability by the joint interrogation of two atomic states}, url = {http://arxiv.org/abs/2104.14309}, year = 2021 }