California-based PsiQuantum has raised $1bn in a Series E round, dubbed by the Financial Times as the “largest funding round for a quantum computing start-up”. Alongside the raise, PsiQuantum also announced a collaboration with Nvidia in areas including quantum algorithms, software and PsiQuantum’s own silicon photonics platform. “Only building the real thing – million-qubit-scale, fault-tolerant machines – will unlock the promise of quantum computing,” said Prof Jeremy O’Brien, PsiQuantum’s co-founder and CEO. We tackled the hardest problems first – at the architectural and chip level – and are now mass-manufacturing best-in-class quantum photonic chips at a leading US semiconductor fab. The company said this design allows the system to cool hundreds of quantum chips in a single cabinet.