For years, the quantum industry has largely measured progress by one number: how many quantum bits, or “qubits”, a machine contains. IBM, Google, and a host of startups have steadily increased qubit counts in the hope that larger processors will eventually become powerful enough to perform useful calculations.
However, Paris-based C12 is making a different bet: more qubits alone are not enough.
The company believes that because qubits are fragile and error-prone, a machine with 1,000 unreliable qubits may ultimately be less useful than one with far fewer, but much more stable, qubits. To back up that vision, this month the startup unveiled a roadmap leading from its first logical qubit in 2027 to a fault-tolerant quantum computer by 2033.
“We had this intuition from the start: it is better to improve the quality of the qubit and the material itself than simply to increase the number of qubits,” said Pierre Desjardins, C12 co-founder and CEO. “In quantum error correction, the key question is how many physical qubits you need to create one logical qubit. The poorer the qubits, the more redundancy you need. We believe we can achieve the same logical qubit with far fewer physical qubits, which has an enormous impact on the ability to scale.”
