Quantinuum announced on Monday that its current generation of quantum hardware scales well beyond the breakeven point. The company reported that each step up in the size of logical qubits improved some performance measures by a factor of over 10.
Logical qubits link collections of hardware qubits to detect and correct errors. More hardware qubits generally help identify errors, but they also increase the chance of new mistakes. If the hardware error rate is too high, growing the logical qubit makes matters worse. Several companies have previously shown hardware with error rates low enough to pass the breakeven point, where adding more qubits improves performance. However, those improvements were not dramatic. Running complex algorithms would have required an impractical number of qubits for each logical qubit to lower error rates sufficiently.