Insider Brief
Alice & Bob has proposed a five-part framework for evaluating logical qubit claims, arguing that the industry needs a common standard to assess progress toward fault-tolerant quantum computing.
The framework evaluates whether a logical qubit outperforms physical qubits, improves as error-correction resources scale, operates across enough correction cycles, avoids post-selection, and remains stable over timescales relevant to practical computation.
The report concludes that while recent demonstrations such as Google’s beyond-breakeven surface code results represent meaningful progress, significant technical challenges remain before logical qubits can support large-scale fault-tolerant quantum computing.
As the quantum computing sector has evolved, so has the way performance is measured. Early on, qubit count — the number of quantum bits in a processor — was viewed as a key benchmark. Today, researchers increasingly argue that raw qubit count matters less than the number of logical qubits, which can reliably perform computations despite errors.
