Silicon-Nitride Waveguide Splitter for Light Delivery to High-Fidelity Matter Qubits

Precise and accurate addressing of individual qubits is necessary in order to create a high-fidelity quantum system. For many matter-based systems, well-focused lasers are a common mechanism to interact with qubits, and are generally routed to the qubits via bulk optics on a table. However, these optics are susceptible to noise and thermal drift, and addressing specific qubits without crosstalk or scatter from other beams presents a significant challenge. Here we show a scalable visible-light silicon-nitride photonics waveguide splitter capable of low crosstalk addressing of individual qubits, modeled as an unevenly-spaced trapped ion system. Our system shows at least an order of magnitude increase in optical isolation compared to existing waveguide devices, requiring only single fiber inputs to address multiple ions. As a silicon chip, it is able to be mass-produced by foundries and tailored to arbitrary visible frequencies. This device should make the development of stable, low-noise matter-based quantum computing systems more feasible.

Approved for Public Release; Distribution Unlimited: AFRL-2023-6147 / 2023-1139