Photonic Engine for Ion-trap Qubit (PhoEnIQ)

Objective

"Quantum computing promises to solve classes of problems that are intractable for classical computers, including the simulation of complex molecules, large-scale optimization, and secure communication. Trapped-ion quantum processors stand out for their excellent qubit coherence and high-fidelity gates. Yet their scalability remains hindered by the reliance on complicated bulk optics and externally delivered laser systems, which are expensive and difficult to maintain. Integrated photonics offers a pathway beyond these limitations by providing scalable optical couplers and routing circuits with improved system stability. So far, however, its role has been restricted mainly to passive optics, while integrating high-coherence laser sources and active optical modulators has proven far more challenging. This difficulty arises from the extreme performance requirements: the qubit addressing laser must achieve linewidths on the order of ~1 Hz, a demanding target for any integrated source. These constraints have prevented integrated photonics from fully replacing the bulky optical systems currently used in ion-trap quantum processors. This project proposes to merge the strengths of both fields by using on-chip microphotonic frequency sources, as the ""engine"" for trapped ion qubits. The laser source is based-on foundry-based, high-Q integrated microresonators to improve its coherence. Monolithic piezoelectric control stabilizes the integrated laser to external highly-stable references to meet the requirements of qubit addressing. The piezoelectric control simultaneously drives high-speed, phase-coherent operations in multi-zone trapped-ion systems. Specifically, the proposal aims to harness these capabilities to realize high-speed, coherent qubit operations in an integrated multi-zone Ca+ trap. The proposed method eliminates critical bulk optics components from the control path for scalable ion control using fully integrated photonic hardware."