Current experimental systems contain fewer than 200 qubits. IBM encountered crosstalk interference when scaling its Condor chip to 433 qubits and subsequently adopted low-density parity-check code requiring 90% fewer qubits than Google’s surface code method, though this requires longer connections between distant qubits.
Google plans to reduce component costs tenfold to achieve its $1 billion target price for a full-scale machine. Amazon Web Services quantum hardware executive Oskar Painter told FT he estimates useful quantum computers remain 15-30 years away, citing engineering challenges in scaling despite resolved fundamental physics problems.
