Reliable Quantum Operations Per Second (rQOPS)

This protocol was introduced by Microsoft in 2023 by C. Nayak [1].

Motivation

Microsoft introduced the reliable Quantum Operations Per Second (rQOPS) figure of merit to evaluate the performance of large-scale, fault-tolerant quantum computers. The principal motivation behind this figure of merit is quantifying the number of reliable logical operations a quantum computer can perform per second.

Protocol details

The number of rQOPS is defined by the product of the number of logical qubits \(n\) and the logical clock frequency \(f\):

The author specifies that the logical error rate should be reported along with the value of the \(rQOPS\).

Limitations

While the rQOPS metric provides a useful high-level indicator of performance, it is subject to several limitations arising from a lack of specification:

• The protocols used to measure the logical error rate and the logical clock frequency are not specified.
• The number of logical qubits \(n\) is not fixed. As a result, the \(rQOPS\) value may not accurately reflect performance at scale. For instance, the rQOPS derived from a small subset of logical qubits may not extrapolate to the full system, especially if clock frequency degrades with increasing system size due to routing or control overheads.

References

1. [1]C. Nayak, “Microsoft achieves first milestone towards a quantum supercomputer.” 2023 [Online]. Available at: https://azure.microsoft.com/en-us/blog/quantum/2023/06/21/microsoft-achieves-first-milestone-towards-a-quantum-supercomputer/