Integration of single-photon from a trapped ion into a photonic chip

Trapped ions are promising qubit systems for implementing quantum networks because of their long coherence times, ability to generate entangled photons as well as high fidelity single- and two-qubit gates. To establish quantum networks in a scalable way, we need photonic integrated circuits to interfere single photons from trapped ions and entangle different trapped ion systems on-demand. However, every trapped ion has strong dipole transitions in ultra-violet and visible wavelength and emits entangled single photons in that regime making them incompatible for present-day photonic foundry. In this work, we integrate the single photons from a trapped barium ion in a photonic Mach-Zehnder interferometer which can be used as a building block of photonic processors for implementing large quantum networks. For this integration, we first generate C-band telecom single photons from barium ions. Then, we integrate and route these single photons into foundry fabricated silicon nitride Mach-Zehnder interferometer. These results will enable a new generation of compact and reconfigurable integrated photonic devices that can serve as efficient quantum interconnects for quantum computers and sensors.