Single-shot readout of a superconducting qubit using a thermal detector

András M. Gunyhó, Suman Kundu, Jian Ma, Wei Liu, Sakari Niemelä, Giacomo Catto, Vasilii Vadimov, Visa Vesterinen, Priyank Singh, Qiming Chen, Mikko Möttönen (Corresponding Author)

Research output: Contribution to journalArticleScientificpeer-review

1 Citation (Scopus)


Measuring the state of a qubit is a key fundamental operation of a quantum computer. High-fidelity single-shot readout of superconducting qubits can be achieved using parametric amplifiers at millikelvin temperatures. However, scaling parametric amplifiers beyond hundreds of qubits is challenging due to practical size and power limitations. Nanobolometers can, in contrast, offer scalability, sensitivity and speed suitable for qubit readout. Here we show that a bolometer can provide single-shot qubit readout with a readout duration of 13.9 μs and a single-shot fidelity of 0.618. The fidelity is mainly limited by the energy relaxation time of the qubit (28 μs), and a fidelity of 0.927 is found after removing errors arising from this relaxation. In the future, higher-fidelity single-shot readout may be achieved through improvements in chip design and experimental setup, as well as a change in the bolometer absorber material to reduce the readout time to the level of hundreds of nanoseconds and below.

Original languageEnglish
Pages (from-to)288-298
Number of pages11
JournalNature Electronics
Issue number4
Publication statusPublished - Apr 2024
MoE publication typeA1 Journal article-refereed


We acknowledge funding from the Academy of Finland Centre of Excellence program project nos. 352925 (A.M.G. and S.K.), 336810 (A.M.G., V. Vadimov and S.K.), 336817 (M.M. and V. Vesterinen) and 336819 (M.M. and V. Vesterinen); European Research Council under Advanced Grant no. 101053801 (ConceptQ) (M.M. and V. Vadimov); Horizon Europe programme HORIZON-CL4-2022-QUANTUM-01-SGA via the project 101113946 (OpenSuperQPlus100) (M.M. and Q.C.); the Future Makers Program of the Jane and Aatos Erkko Foundation and the Technology Industries of Finland Centennial Foundation (A.M.G., Q.C. and P.S.); Business Finland under the Quantum Technologies Industrial (QuTI) project (decision no. 41419/31/2020) (S.N., J.M. and M.M.); and the Finnish Foundation for Technology Promotion project no. 8640 (G.C.).


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