How to Benchmark Logical Qubit Claims

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. But ask what those benchmarking claims about logical qubits actually mean — how to compare them, what standard they’re being held to — and the answer gets complicated fast. That’s the problem quantum computing startup Alice & Bob set out…