Microsoft Quantum, QOLAB Propose Higher Bar For ‘Scalable’ Logical Qubits

Insider Brief

• Microsoft Quantum and QOLAB proposed a framework for assessing whether logical qubits can scale into fault-tolerant systems capable of useful quantum computations.
• The paper says scalable logical qubits should be evaluated across reliability, scale, capability and performance, rather than through qubit counts or isolated error-rate results.
• The framework calls for repeated error correction, universal fault-tolerant operations, low-latency feedback and a credible route to operating hundreds or thousands of logical qubits.

A framework from Microsoft Quantum and QOLAB proposes that quantum computing’s next progress reports should be judged by more than a rising count of logical qubits.

The paper, posted on arXiv by Microsoft Quantum researchers Matthias Troyer and Chetan Nayak and QOLAB’s John Martinis, introduces the term “scalable logical qubit” for an error-corrected qubit that can support long computations, execute a full set of fault-tolerant operations and be replicated into systems containing hundreds or thousands of logical qubits.

The proposal is ultimately aimed at a more demanding common standard for evaluating an increasingly crowded field of quantum error-correction demonstrations.