First silicon-based quantum computer encodes 2 logical qubits using 4 physical nuclear spins; performs full-stack logical operations

https://phys.org/news/2026-03-silicon-quantum-logical.html

"applying [[4,2,2]] quantum error-detecting code to phosphorus atoms' spins makes fault-tolerant... successful with: difficult T-gate which is final key to perform any complex quantum algorithm, Variational Quantum Eigensolver algorithm calculating water molecule's ground-state energy... other platforms (like superconducting qubits) have reached similar milestones, but silicon is scalable: quantum computers could eventually be mass-produced using existing semiconductor fabrication plants"