Chip scale coil stabilized Brillouin laser driving a room temperature trapped ion qubit.

Photonic integrated stable, ultra-low-noise lasers are essential for scalable and portable quantum information systems. Trapped ions are a leading modality for quantum computing and optical clocks, with room-temperature operation enabling portable applications. Current systems rely on free-space lasers and stabilization cavities, frequency conversion, and cryogenic infrastructure, limiting size, weight, and power. We demonstrate a chip-scale coil-stabilized 674 nm Brillouin laser driving qubit state preparation and measurement and the optical clock transition in a room-temperature surface electrode trapped Sr ion without a bulk-optic reference cavity. The CMOS compatible silicon nitride integrated 3-meter coil and Brillouin laser achieve 8.8×10 stability at 20 ms, sufficient to interrogate the 0.4 Hz quadrupole optical clock transition. The ion-disciplined laser achieves 5.3 stability, spectroscopy with 1.5 kHz linewidths, and 99.6% qubit state preparation and measurement fidelity. These results light the way towards integration of stabilized lasers with trapped-ion chips for portable and robust quantum technologies.