Imaging optical frequencies with 100 $\mu$Hz precision and 1.1 $\mu$m resolution

TL;DR

This paper demonstrates high-precision imaging spectroscopy of a lattice-trapped fermionic Sr optical clock, achieving record frequency stability and resolution, enabling advanced studies in quantum coherence and fundamental physics.

Contribution

It introduces a method combining micron-scale imaging with submillihertz spectral precision on an optical clock transition.

Findings

Achieved 15 seconds of atomic coherence on the clock transition.

Reached a record frequency precision of 2.5×10⁻¹⁹.

Recorded the narrowest Rabi linewidth of 150 mHz on a coherent optical transition.

Abstract

We implement imaging spectroscopy of the optical clock transition of lattice-trapped degenerate fermionic Sr in the Mott-insulating regime, combining micron spatial resolution with submillihertz spectral precision. We use these tools to demonstrate atomic coherence for up to 15 s on the clock transition and reach a record frequency precision of $2.5\times 10^{-19}$. We perform the most rapid evaluation of trapping light shifts and record a 150 mHz linewidth, the narrowest Rabi line shape observed on a coherent optical transition. The important emerging capability of combining high-resolution imaging and spectroscopy will improve the clock precision, and provide a path towards measuring many-body interactions and testing fundamental physics.