Coherent Three-Photon Excitation of the Strontium Clock Transition

TL;DR

This paper demonstrates a novel three-photon excitation method for strontium atoms, achieving high contrast and efficient state transfer, advancing quantum simulation and atom laser technologies.

Contribution

It introduces coherent three-photon excitation and STIRAP-like transfer for strontium, overcoming previous limitations and measuring atomic loss coefficients.

Findings

Achieved 51% contrast in three-photon excitation

Demonstrated successful three-photon STIRAP-like transfer

Measured two-body loss coefficient of $^{84}$Sr atoms

Abstract

We demonstrate coherent three-photon excitation of the strontium clock transition with a contrast of 51(12)% using a Bose-Einstein condensate. We follow it up with a demonstration of three-photon STIRAP-like transfer, overcoming the typical limitations of this technique to odd-level numbers. We also measure the two-body loss coefficient of $^{84}$Sr clock-state atoms. Our work constitutes an essential step towards outcoupling a continuous atom laser beam and provides a fast excitation mechanism for quantum simulation using bosonic alkaline-earth-like atoms.