Collection of fluorescence from an ion using trap-integrated photonics

TL;DR

This paper demonstrates a novel integrated photonics approach to efficiently collect and manipulate photons emitted from a trapped ion, enabling scalable quantum information processing with improved stability and reproducibility.

Contribution

It introduces a waveguide-integrated grating on a microfabricated ion-trap chip for stable, efficient photon collection from a trapped ion, advancing scalable quantum systems.

Findings

Achieved passive phase stability in photon collection

Demonstrated efficient coupling of emitted photons into a single optical mode

Enabled detection of the ion's quantum state using integrated optics

Abstract

Spontaneously emitted photons are entangled with the electronic and nuclear degrees of freedom of the emitting atom, so interference and measurement of these photons can entangle separate matter-based quantum systems as a resource for quantum information processing. However, the isotropic nature of spontaneous emission hinders the single-mode photonic operations required to generate entanglement. Current demonstrations rely on bulk photon-collection and manipulation optics that suffer from environment-induced phase instability, mode matching challenges, and system-to-system variability, factors that impede scaling to the large numbers of entangled pairs needed for quantum information processing. To address these limitations, we demonstrate a collection method that enables passive phase stability, straightforward photonic manipulation, and intrinsic reproducibility. Specifically, we engineer a waveguide-integrated grating to couple photons emitted from a trapped ion into a single optical mode within a microfabricated ion-trap chip. Using the integrated collection optic, we characterize the collection efficiency, image the ion, and detect the ion's quantum state. This proof-of-principle demonstration lays the foundation for leveraging the inherent stability and reproducibility of integrated photonics to efficiently create, manipulate, and measure multipartite quantum states in arrays of quantum emitters.