Experimental Bayesian estimation of quantum state preparation, measurement, and gate errors in multi-qubit devices
Autor: | Haggai Landa, Dekel Meirom, Naoki Kanazawa, Mattias Fitzpatrick, Christopher J. Wood |
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Rok vydání: | 2021 |
Předmět: | |
DOI: | 10.48550/arxiv.2108.10686 |
Popis: | We introduce a Bayesian method for the estimation of single qubit errors in quantum devices, and use it to characterize these errors on three 27-qubit superconducting qubit devices. We self-consistently estimate up to seven parameters of each qubit's state preparation, readout, and gate errors, analyze the stability of these errors as a function of time, and demonstrate easily implemented approaches for mitigating different errors before a quantum computation experiment. On the investigated devices we find non-negligible qubit reset errors that cannot be parametrized as a diagonal mixed state, but manifest as a coherent phase of a superposition with a small contribution from the qubit's excited state. We are able to mitigate such errors by applying pre-rotations on the initialized qubits, which we demonstrate with multi-qubit entangled states. Our results demonstrate that Bayesian estimation can resolve small parameters - including those pertaining to quantum gate errors - with a high relative accuracy, at a lower measurement cost as compared with standard characterization approaches. Comment: v3 contains small corrections and clarifications |
Databáze: | OpenAIRE |
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