Parity-Doublet Coherence Times in Optically Trapped Polyatomic Molecules

TL;DR

This paper demonstrates long coherence times in optically trapped CaOH polyatomic molecules by exploiting parity-doublet states, advancing their potential for quantum information and precision measurement applications.

Contribution

It reports the first measurement of parity-doublet coherence times in optically trapped polyatomic molecules, achieving a coherence time of 0.8 seconds by suppressing differential Stark shifts.

Findings

Achieved a coherence time of 0.8 seconds in CaOH molecules.

Suppressed differential Stark shifts using molecular spectroscopy.

Identified parity-dependent trap shifts as a limiting factor.

Abstract

Polyatomic molecules provide complex internal structures that are ideal for applications in quantum information science, quantum simulation, and precision searches for physics beyond the Standard Model. A key feature of polyatomic molecules is the presence of parity-doublet states. These structures, which generically arise from the rotational and vibrational degrees of freedom afforded by polyatomic molecules, are a powerful feature to pursue these diverse quantum science applications. Linear triatomic molecules contain $\ell$-type parity doublet states, which are predicted to exhibit robust coherence properties. We optically trap CaOH molecules, prepare them in $\ell$-type parity-doublet states, and realize a bare qubit coherence time of $T_2^* = 0.8(2)$ s. We suppress differential Stark shifts by employing molecular spectroscopy to cancel ambient electric fields, and characterize parity-dependent trap shifts, which are found to limit the coherence time. The parity-doublet coherence times achieved in this work are a defining milestone for the use of polyatomic molecules in quantum science.