The company, whose mission is "building the world’s first useful general purpose quantum computer," is focused on an approach using silicon photonic qubits produced in a conventional semiconductor fab. Photonics, says the company, is the only way to deliver 1,000,000 qubits - the minimum amount required for a "useful" quantum computer.
"Thirty years ago photonic quantum computing was believed impossible; twenty years ago, it was proved possible but dismissed as impractical," says the company. "Today, after numerous architectural breakthroughs and advances in silicon photonics, PsiQuantum uniquely has a clear path to a useful quantum computer."
The company's approach is based on a custom silicon chip intersected by tiny mirrors. Photons travel along pathways on the chip and the mirrors "bounce" them into an entangled state, says the company, thus facilitating computation. A sensor then measures the entangled photons allowing calculations to be performed to read their output.
The company has said that with its technology and resulting scalability, it believes it can build a quantum computer featuring a million qubits within a "handful of years." The company has reportedly already begun manufacturing quantum chips with the help of semiconductor foundry GlobalFoundries.
The company raised $230 million last year - reportedly one of the biggest investments in quantum computing to date at that time. The latest funding round was led by Atomico and included investment by BlackRock, Founders Fund, and Redpoint Ventures. Other previous investors include Microsoft's M12 venture capital subsidiary, Playground Global, and Quantum1 Group.
Microsoft, while investing in PsiQuantum, is also building its own quantum computer, but using a different approach.
Samir Kumar, managing director at Microsoft M12 says, "It's worth noting that PsiQuantum’s approach is different from Microsoft’s efforts in topological qubits (Microsoft’s approach would enable error correction in hardware via topological protection from local noise). PsiQuantum and Microsoft have different sets of engineering challenges to address with their distinct approaches, but the companies share the vision for