A high-performance optical lattice clock based on bosonic atoms

TL;DR

This paper presents a highly stable and accurate bosonic optical lattice clock with performance surpassing previous fermionic clocks, enabled by ultra-long interrogation times and advanced stabilization techniques.

Contribution

It demonstrates a bosonic optical lattice clock achieving record stability and accuracy, expanding the potential applications of bosonic clocks in high-precision and space-based scenarios.

Findings

Achieved 3×10⁻¹⁸ instability and 2.0×10⁻¹⁷ accuracy.

Used 4 s interrogation time with cryogenic silicon resonator.

Measured isotope shift with 12 mHz uncertainty.

Abstract

Optical lattice clocks with uncertainty and instability in the $10^{-17}$-range and below have so far been demonstrated exclusively using fermions. Here, we demonstrate a bosonic optical lattice clock with $3\times 10^{-18}$ instability and $2.0\times 10^{-17}$ accuracy, both values improving on previous work by a factor 30. This was enabled by probing the clock transition with an ultra-long interrogation time of 4 s, using the long coherence time provided by a cryogenic silicon resonator, by careful stabilization of relevant operating parameters, and by operating at low atom density. This work demonstrates that bosonic clocks, in combination with highly coherent interrogation lasers, are suitable for high-accuracy applications with particular requirements, such as high reliability, transportability, operation in space, or suitability for particular fundamental physics topics. As an example, we determine the $^{88}\textrm{Sr} - ^{87}$Sr isotope shift with 12 mHz uncertainty.