A 6-Qubit Electron Spin Quantum Computer in the cloud*

Quantum Inspire (www.quantum-inspire.com) is a cloud platform giving access to quantum computers based on superconducting and semiconducting qubits (electrons in SiGe heterostructures) and an emulator. In 2020 it was launched with a 2-qubit Si QPU. We have incorporated a new 6-qubit chip, developed at QuTech, based on isotopically purified ²⁸Si to maximize spin coherence (Philips, S.G.J., Mądzik, M.T., Amitonov, S.V. et al. Universal control of a six-qubit quantum processor in silicon. Nature 609, 919–924 (2022)) in a full stack, cloud accessible quantum computer. Rabi frequencies are on the order of few MHz. Qubit initialization and measurement is done using Pauli spin blockade, combined with active feedback and post-selection. The stack includes a full control system, automated tuning and calibration to provide continuous availability, compilers, and account and data management facilities. It can be used in tandem with a classical runtime to execute hybrid quantum-classical algorithms and is provided with an software development kit for programming in Python plus a web GUI for users less familiar with quantum programming. We will present the latest results on the functionality and performance of the system, which is freely accessible to everyone. We will also present a preview of our roadmap towards a 200-qubit chip in the European flagship programs.