Top Silicon Spin Quantum Computing Companies 2026: Complete Vendor Guide

The leading top silicon spin quantum computing companies in 2026 build their qubits from single electron spins. Each electron sits in a tiny quantum dot etched into silicon or germanium. These dots are made on the same 300mm CMOS production lines that turn out ordinary logic chips. This shared manufacturing path gives silicon spin the deepest route to scale of any quantum architecture. The eight commercial vendors split into three design families. Five build gate-defined quantum dots on silicon-28 (Intel, Diraq, Quantum Motion, Equal1, Quobly). One uses atomic-precision donor qubits (Silicon Quantum Computing), one uses germanium quantum dots (Groove Quantum), and one uses silicon T-centre spin-photon qubits (Photonic Inc). The pace of progress turned sharp in late 2025. In December 2025 SQC reached 99.99% two-qubit fidelity, which matched the trapped-ion industry record. Diraq separately showed working qubits at 1 Kelvin, which means silicon spin can scale without a full dilution refrigerator. These vendors are the youngest slice of the quantum-hardware industry, yet also the fastest growing. DARPA QBI Stage B picked four of the eight in November 2025, and total funding across the field crossed $900M entering 2026. Silicon spin has the shortest commercial history of any major modality. The…