Demonstration of a Timescale Based on a Stable Optical Carrier

Abstract

We demonstrate a time scale based on a phase stable optical carrier that accumulates an estimated time error of 48 ± 94 ps over 34 days of operation. This all-optical time scale is formed with a cryogenic silicon cavity exhibiting improved long-term stability and an accurate 87 Sr lattice clock. We show that this new time scale architecture outperforms existing microwave time scales, even when they are steered to optical frequency standards. Our analysis indicates that this time scale is capable of reaching a stability below 1 × 10 −17 after a few months of averaging, making timekeeping at the 10 −18 level a realistic prospect. arXiv:1907.03184v1 [physics.atom-ph]

Precision Metrology Meets Cosmology: Improved Constraints on Ultralight Dark Matter from Atom-Cavity Frequency Comparisons

“…Integrated with a microwave timescale, future timekeeping systems will be able to extend the discovery reach of these searches for dark matter induced variation of fundamental constants. Indeed, the data presented here is a subset of that used to demonstrate an all-optical timescale with record low timing error over one month of operation [50]. As ultrastable laser technologies and laser cooling techniques advance to include atomic species with highly relativistic clock transitions in neutral atoms, ions, highly charged ions, and nuclei, the resolution with which these effects can be resolved is expected to advance greatly.…”

“…In this Letter we demonstrate significantly improved bounds on the coupling of ultralight dark matter to the fine-structure constant (α) and electron mass (m e ). Central to this important advance is the state-of-the-art stability of our 21 cm crystalline silicon optical cavity at 124 K [46][47][48] and measuring its frequency with both a Sr optical lattice clock with an estimated accuracy of 2.0 × 10 −18 [49] and a hydrogen maser [50]. Fig.…”

“…Data for f H /f c is longer in duration, has significantly fewer gaps, and is dominated by white noise, but nonetheless the power spectrum is evaluated with the same procedure as f Sr /f c . Due to the worse short-term stability of f H /f c and the presence of significant microwave link noise at high frequencies [50], data for the maser is plotted only for frequencies below 1 mHz [53].…”

Demonstration of the nearly continuous operation of an171Yb optical lattice clock for half a year

“…The continuous operation of an optical lattice clock is essential for the calibration of the frequency of TAI as a secondary representation of the second [8] as well as the absolute frequency measurement. A robust lattice clock is also important for new applications including tests of fundamental physics [12,19,[22][23][24][25][26], relativistic geodesy [27,28], and the generation of a stable local timescale [13,[29][30][31].…”

Vortex pinning in the superfluid core of neutron stars and the rise of pulsar glitches

“…Pulsars are neutron stars (NSs) spinning very rapidly with extremely stable periods. With relative delays as small as 10 −21 , some pulsars outperform the most accurate terrestrial clocks (Milner et al 2019). Nevertheless, irregularities have been detected in long-term pulsar timing observations.…”