C-band single photons from a trapped ion via two-stage frequency conversion

TL;DR

This paper demonstrates converting photons emitted by a trapped Ba+ ion into telecommunications wavelengths, facilitating integration of trapped ions into fiber-based quantum networks for long-distance quantum communication.

Contribution

It introduces a two-stage frequency conversion process for trapped ion photons to the C-band, bridging the gap between ion emission and telecom fiber compatibility.

Findings

Successful frequency conversion of Ba+ ion photons to C-band

Enhanced prospects for long-distance trapped ion quantum networks

Demonstration of a key step towards quantum internet infrastructure

Abstract

Fiber-based quantum networks require photons at telecommunications wavelengths to interconnect qubits separated by long distances. Trapped ions are leading candidates for quantum networking with high-fidelity two-qubit gates, long coherence times, and the ability to readily emit photons entangled with the ion's internal qubit states. However, trapped ions typically emit photons at wavelengths incompatible with telecommunications fiber. Here, we demonstrate frequency conversion of visible photons, emitted from the S-P dipole transition of a trapped Ba+ ion, into the telecommunications C-band. These results are an important step towards enabling a long-distance trapped ion quantum internet.