2021/09/20 by May E. Kim, Kim, May E., William F. McGrew +21
Medicine · Physics and Astronomy · #Advanced Fiber Laser Technologies #Advanced Frequency and Time Standards #Atomic Physics (physics.atom-ph) #Atomic and Subatomic Physics Research #Cardiovascular Syncope and Autonomic Disorders #FOS: Physical sciences #Optics (physics.optics)
paper · pdf · doi:10.48550/arxiv.2109.09540
openalex publication_date 2021/09/20 · openalex created_date 2022/07/25 · openalex updated_date 2026/07/28
Comparisons of high-accuracy optical atomic clocks citeLudlow2015 are\nessential for precision tests of fundamental physics citeSafronova2018,\nrelativistic geodesy citeMcGrew2018, Grotti2018, Delva2019, and the\nanticipated redefinition of the SI second citeRiehle2018. The scientific\nreach of these applications is restricted by the statistical precision of\ninterspecies comparison measurements. The instability of individual clocks is\nlimited by the finite coherence time of the optical local oscillator (OLO),\nwhich bounds the maximum atomic interrogation time. In this letter, we\nexperimentally demonstrate differential spectroscopy citeHume2016, a\ncomparison protocol that enables interrogating beyond the OLO coherence time.\nBy phase-coherently linking a zero-dead-time (ZDT) citeSchioppo2017 Yb\noptical lattice clock with an Al+ single-ion clock via an optical frequency\ncomb and performing synchronised Ramsey spectroscopy, we show an improvement in\ncomparison instability relative to our previous result\n citenetwork2020frequency of nearly an order of magnitude. To our knowledge,\nthis result represents the most stable interspecies clock comparison to date.\n