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

TL;DR

This study uses advanced atomic clocks and cavity resonators to set new constraints on ultralight dark matter coupling, extending the search range and improving sensitivity compared to previous spectroscopic methods.

Contribution

It introduces a novel frequency comparison method utilizing atomic clocks and cavity resonators to improve bounds on ultralight dark matter interactions.

Findings

Set new bounds on ultralight dark matter coupling in the mass range of 10^{-16} to 10^{-21} eV.

Extended the search range to higher masses using dynamical decoupling techniques.

Demonstrated the effectiveness of atomic clock comparisons for fundamental physics tests.

Abstract

We conduct frequency comparisons between a state-of-the-art strontium optical lattice clock, a cryogenic crystalline silicon cavity, and a hydrogen maser to set new bounds on the coupling of ultralight dark matter to Standard Model particles and fields in the mass range of $10^{-16}$ $-$ $10^{-21}$ eV. The key advantage of this two-part ratio comparison is the differential sensitivities to time variation of both the fine-structure constant and the electron mass, achieving a substantially improved limit on the moduli of ultralight dark matter, particularly at higher masses than typical atomic spectroscopic results. Furthermore, we demonstrate an extension of the search range to even higher masses by use of dynamical decoupling techniques. These results highlight the importance of using the best performing atomic clocks for fundamental physics applications as all-optical timescales are increasingly integrated with, and will eventually supplant, existing microwave timescales.