IonQ spun out of research at the University of Maryland and Duke. It builds on Trapped ion qubits, the same core technology as Quantinuum: ytterbium ions held by electromagnetic fields, with gates driven by lasers coupling the ions' internal states to their shared motion in the trap. IonQ keeps its ions in a single linear chain rather than shuttling them between zones, giving natural all-to-all connectivity without Quantinuum's QCCD rearrangement.
IonQ was the first pure-play quantum computing company to go public on a US stock exchange. It sells cloud access through AWS Braket, Azure Quantum, and Google Cloud Marketplace rather than only its own platform.