Qubit readout error mitigation with bit-flip averaging

Quantum computers are becoming increasingly accessible and may soon outperform classical computers for useful tasks. However, qubit readout errors remain a substantial hurdle to running quantum algorithms on current devices. We present a scheme to more efficiently mitigate these errors on quantum hardware and numerically show that our method consistently gives advantage over previous mitigation schemes. Our scheme removes biases in the readout errors, allowing a general error model to be built with far fewer calibration measurements. Specifically, for reading out n-qubits, we show a factor of 2(n) reduction in the number of calibration measurements without sacrificing the ability to compensate for correlated errors. Our approach can be combined with, and simplify, other mitigation methods, allowing tractable mitigation even for large numbers of qubits.

Automated summary

A new scheme is proposed to more efficiently mitigate qubit readout errors on quantum hardware, consistently giving advantage over previous mitigation schemes. The method reduces the number of calibration measurements for reading out n-qubits, without sacrificing the ability to compensate for correlated errors. This approach can be combined with other methods to simplify mitigation for a large number of qubits.