The Quantum Platforms Briefing — Day 4: Google Quantum AI

Cirq, qsim/QVM, and access model realities — Google Quantum Offerings (Quantum AI & QCS) — Current Landscape, Developer Guide, and Comparative Analysis.

Google Quantum AI (Quantum Computing Service & tools) — Google’s quantum computing portfolio today includes a by-approval cloud service for running programs on Google’s superconducting quantum processors, plus a suite of open-source libraries and simulators for developers. The flagship Quantum Computing Service (QCS) — accessible via the Quantum Engine API — allows approved users to execute Cirq quantum circuits on Google’s cutting-edge chips (e.g. the 54-qubit Sycamore family, and a new 105-qubit “Willow” processor) [1][2]. However, QCS remains in restricted preview: there is no public self-service access as of 2025 [3]. Instead, Google grants usage to select partners (often research institutions) — no usage fees are charged currently (it’s not a commercial product yet) [4]. This means that unlike AWS or IBM’s quantum clouds, general businesses cannot yet “pay and play” with Google’s quantum hardware.

On the tooling side, Google actively supports Cirq, a Python framework for quantum circuits, along with high-performance simulators like qsim and the Quantum Virtual…