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Direct manipulation of a superconducting spin qubit strongly coupled to a transmon qubit

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Spin qubits in semiconductors are a promising platform for producing highly scalable quantum computing devices. However, it is difficult to realize multiqubit interactions over extended distances. Superconducting spin qubits provide an alternative by encoding a qubit in the spin degree of freedom of an Andreev level. These Andreev spin qubits have an intrinsic spin–supercurrent coupling that enables the use of recent advances in circuit quantum electrodynamics. The first realization of an Andreev spin qubit encoded the qubit in the excited states of a semiconducting weak link, leading to frequent decay out of the computational subspace. Additionally, rapid qubit manipulation was hindered by the need for indirect Raman transitions. Here we use an electrostatically defined quantum dot Josephson junction with large charging energy, which leads to a spin-split doublet ground state. We tune the qubit frequency over a frequency range of 10 GHz using a magnetic field, which also enables us to investigate the qubit performance using direct spin manipulation. An all-electric microwave drive produces Rabi frequencies exceeding 200 MHz. We embed the Andreev spin qubit in a superconducting transmon qubit, demonstrating strong coherent qubit–qubit coupling. These results are a crucial step towards a hybrid architecture that combines the beneficial aspects of both superconducting and semiconductor qubits.

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Fig. 1: ASQ.
Fig. 2: Coherent manipulation of the ASQ.
Fig. 3: Coherence of the ASQ.
Fig. 4: Coherent ASQ–transmon coupling.

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Data availability

The data that support the findings of this study are publicly available via 4TU.ResearchData at

Code availability

The analysis code that supports the findings of this study is publicly available via 4TU.ResearchData at


  1. Loss, D. & DiVincenzo, D. P. Quantum computation with quantum dots. Phys. Rev. A 57, 120 (1998).

    ADS  Google Scholar 

  2. Hanson, R., Kouwenhoven, L. P., Petta, J. R., Tarucha, S. & Vandersypen, L. M. K. Spins in few-electron quantum dots. Rev. Mod. Phys. 79, 1217 (2007).

    ADS  Google Scholar 

  3. Koch, J. et al. Charge-insensitive qubit design derived from the Cooper pair box. Phys. Rev. A 76, 042319 (2007).

    ADS  Google Scholar 

  4. Zwerver, A. M. J. et al. Qubits made by advanced semiconductor manufacturing. Nat. Electron. 5, 184–190 (2022).

    Google Scholar 

  5. Mi, X. et al. A coherent spin–photon interface in silicon. Nature 555, 599–603 (2018).

    ADS  Google Scholar 

  6. Samkharadze, N. et al. Strong spin-photon coupling in silicon. Science 359, 1123–1127 (2018).

    ADS  Google Scholar 

  7. Landig, A. J. et al. Coherent spin–photon coupling using a resonant exchange qubit. Nature 560, 179–184 (2018).

    ADS  Google Scholar 

  8. Borjans, F., Croot, X. G., Mi, X., Gullans, M. J. & Petta, J. R. Resonant microwave-mediated interactions between distant electron spins. Nature 577, 195–198 (2020).

    ADS  Google Scholar 

  9. Harvey-Collard, P. et al. Coherent spin-spin coupling mediated by virtual microwave photons. Phys. Rev. X 12, 021026 (2022).

    Google Scholar 

  10. Yu, C. X. et al. Strong coupling between a photon and a hole spin in silicon. Nat. Nanotechnol. (2023).

  11. Arute, F. et al. Quantum supremacy using a programmable superconducting processor. Nature 574, 505–510 (2019).

    ADS  Google Scholar 

  12. Compute Resources (IBM Quantum, accessed 13 June 2022);

  13. Blais, A. et al. Cavity quantum electrodynamics for superconducting electrical circuits: an architecture for quantum computation. Phys. Rev. A 69, 062320 (2004).

    ADS  Google Scholar 

  14. Wallraff, A. et al. Strong coupling of a single photon to a superconducting qubit using circuit quantum electrodynamics. Nature 431, 162–167 (2004).

    ADS  Google Scholar 

  15. Blais, A., Grimsmo, A. L., Girvin, S. & Wallraff, A. Circuit quantum electrodynamics. Rev. Mod. Phys. 93, 025005 (2021).

    ADS  MathSciNet  Google Scholar 

  16. Chtchelkatchev, N. M. & Nazarov, Y. V. Andreev quantum dots for spin manipulation. Phys. Rev. Lett. 90, 226806 (2003).

    ADS  Google Scholar 

  17. Padurariu, C. & Nazarov, Y. V. Theoretical proposal for superconducting spin qubits. Phys. Rev. B 81, 144519 (2010).

    ADS  Google Scholar 

  18. Béri, B., Bardarson, J. H. & Beenakker, C. W. J. Splitting of Andreev levels in a Josephson junction by spin-orbit coupling. Phys. Rev. B 77, 045311 (2008).

    ADS  Google Scholar 

  19. Hays, M. et al. Coherent manipulation of an Andreev spin qubit. Science 373, 430–433 (2021).

    ADS  MathSciNet  MATH  Google Scholar 

  20. Hays, M. et al. Continuous monitoring of a trapped superconducting spin. Nat. Phys. 16, 1103–1107 (2020).

    Google Scholar 

  21. Park, S. & Yeyati, A. L. Andreev spin qubits in multichannel Rashba nanowires. Phys. Rev. B 96, 125416 (2017).

    ADS  Google Scholar 

  22. Metzger, C. et al. Circuit-QED with phase-biased Josephson weak links. Phys. Rev. Research 3, 013036 (2021).

    ADS  Google Scholar 

  23. Nowack, K. C., Koppens, F. H. L., Nazarov, Y. V. & Vandersypen, L. M. K. Coherent control of a single electron spin with electric fields. Science 318, 1430–1433 (2007).

    ADS  Google Scholar 

  24. Nadj-Perge, S., Frolov, S. M., Bakkers, E. P. A. M. & Kouwenhoven, L. P. Spin–orbit qubit in a semiconductor nanowire. Nature 468, 1084–1087 (2010).

    Google Scholar 

  25. Bargerbos, A. et al. Singlet-doublet transitions of a quantum dot Josephson junction detected in a transmon circuit. PRX Quantum 3, 030311 (2022).

    ADS  Google Scholar 

  26. Bargerbos, A. et al. Spectroscopy of spin-split Andreev levels in a quantum dot with superconducting leads. Preprint at (2022).

  27. Golovach, V. N., Borhani, M. & Loss, D. Electric-dipole-induced spin resonance in quantum dots. Phys. Rev. B 74, 165319 (2006).

    ADS  Google Scholar 

  28. van den Berg, J. W. G. et al. Fast spin-orbit qubit in an indium antimonide nanowire. Phys. Rev. Lett. 110, 066806 (2013).

    ADS  Google Scholar 

  29. Wesdorp, J. J. et al. Microwave spectroscopy of interacting Andreev spins. Preprint at (2022).

  30. Pavešić, L., Pita-Vidal, M., Bargerbos, A. & Žitko, R. Impurity Knight shift in quantum dot Josephson junctions. Preprint at (2022).

  31. Han, L. et al. Variable and orbital-dependent spin-orbit field orientations in an InSb double quantum dot characterized via dispersive gate sensing. Phys. Rev. Appl. 19, 014063 (2023).

    ADS  Google Scholar 

  32. Lazăr, S. et al. Calibration of drive non-linearity for arbitrary-angle single-qubit gates using error amplification. Preprint at (2022).

  33. Werninghaus, M. et al. Leakage reduction in fast superconducting qubit gates via optimal control. npj Quantum Inf. 7, 14 (2021).

    ADS  Google Scholar 

  34. Stockill, R. et al. Quantum dot spin coherence governed by a strained nuclear environment. Nat. Commun. 7, 12745 (2016).

    ADS  Google Scholar 

  35. Hahn, E. L. Spin echoes. Phys. Rev. 80, 580 (1950).

    ADS  MATH  Google Scholar 

  36. Carr, H. Y. & Purcell, E. M. Effects of diffusion on free precession in nuclear magnetic resonance experiments. Phys. Rev. 94, 630 (1954).

    ADS  Google Scholar 

  37. Barthel, C., Medford, J., Marcus, C. M., Hanson, M. P. & Gossard, A. C. Interlaced dynamical decoupling and coherent operation of a singlet-triplet qubit. Phys. Rev. Lett. 105, 266808 (2010).

    ADS  Google Scholar 

  38. Bylander, J. et al. Noise spectroscopy through dynamical decoupling with a superconducting flux qubit. Nat. Phys. 7, 565–570 (2011).

    Google Scholar 

  39. Cywiński, L., Lutchyn, R. M., Nave, C. P. & Das Sarma, S. How to enhance dephasing time in superconducting qubits. Phys. Rev. B 77, 174509 (2008).

    ADS  Google Scholar 

  40. Medford, J. et al. Scaling of dynamical decoupling for spin qubits. Phys. Rev. Lett. 108, 086802 (2012).

    ADS  Google Scholar 

  41. Schreier, J. A. et al. Suppressing charge noise decoherence in superconducting charge qubits. Phys. Rev. B 77, 180502 (2008).

    ADS  Google Scholar 

  42. Braumüller, J. et al. Characterizing and optimizing qubit coherence based on SQUID geometry. Phys. Rev. Appl. 13, 054079 (2020).

    ADS  Google Scholar 

  43. Malinowski, F. K. et al. Symmetric operation of the resonant exchange qubit. Phys. Rev. B 96, 045443 (2017).

    ADS  Google Scholar 

  44. Malinowski, F. K. et al. Spectrum of the nuclear environment for GaAs spin qubits. Phys. Rev. Lett. 118, 177702 (2017).

    ADS  Google Scholar 

  45. Landig, A. J. et al. Virtual-photon-mediated spin-qubit–transmon coupling. Nat. Commun. 10, 5037 (2019).

    ADS  Google Scholar 

  46. Forn-Díaz, P., Lamata, L., Rico, E., Kono, J. & Solano, E. Ultrastrong coupling regimes of light-matter interaction. Rev. Mod. Phys. 91, 025005 (2019).

    ADS  Google Scholar 

  47. Scarlino, P. et al. In situ tuning of the electric-dipole strength of a double-dot charge qubit: charge-noise protection and ultrastrong coupling. Phys. Rev. X 12, 031004 (2022).

    Google Scholar 

  48. de Leon, N. P. et al. Materials challenges and opportunities for quantum computing hardware. Science 372, eabb2823 (2021).

    ADS  Google Scholar 

  49. Hendrickx, N. W. et al. Gate-controlled quantum dots and superconductivity in planar germanium. Nat. Commun. 9, 2835 (2018).

    ADS  Google Scholar 

  50. Scappucci, G. et al. The germanium quantum information route. Nat. Rev. Mater. 6, 926–943 (2021).

    ADS  Google Scholar 

  51. Tosato, A. et al. Hard superconducting gap in germanium. Commun. Mater. 4, 23 (2023).

    Google Scholar 

  52. Spethmann, M., Zhang, X.-P., Klinovaja, J. & Loss, D. Coupled superconducting spin qubits with spin-orbit interaction. Phys. Rev. B 106, 115411 (2022).

    ADS  Google Scholar 

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We acknowledge fruitful discussion with M. Veldhorst, M. Russ, F. Malinowski, V. Fatemi and Y. Nazarov. We further thank P. Krogstrup for guidance in the material growth. This research was inspired by prior work by J.J.W. where the spin-flip transition in an InAs/Al nanowire weak link was directly observed in spectroscopy under the application of a magnetic field29. This research is co-funded by the allowance for Top Consortia for Knowledge and Innovation (TKI) from the Dutch Ministry of Economic Affairs; research project ‘Scalable circuits of Majorana qubits with topological protection’ (i39, SCMQ) with project no. 14SCMQ02; the Dutch Research Council (NWO); and the Microsoft Quantum initiative. R.Ž. acknowledges support from the Slovenian Research Agency (ARRS) under P1-0416 and J1-3008. R.A. acknowledges support from the Spanish Ministry of Science and Innovation through grant PGC2018-097018-B-I00 and from the CSIC Research Platform on Quantum Technologies PTI-001. B.v.H. and C.K.A. acknowledge support from the Dutch Research Council (NWO).

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Authors and Affiliations



A.B., M.P.-V. and A.K. conceived the experiment. Y.L. developed and provided the nanowire materials. A.B., M.P.-V., L.J.S., L.G. and J.J.W. prepared the experimental setup and data acquisition tools. L.J.S. deposited the nanowires. A.B. and M.P.-V. designed and fabricated the device, performed the measurements and analysed the data, with continuous feedback from L.J.S., L.G., J.J.W., B.v.H., A.K. and C.K.A. R.A., B.v.H. and R.Ž. provided theory support during and after the measurements. A.B., M.P.-V. and B.v.H. wrote the code to compute the circuit energy levels and extract the experimental parameters. L.P.K., R.A., B.v.H., A.K. and C.K.A. supervised the work. A.B., M.P.-V. and C.K.A. wrote the paper with feedback from all authors.

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Correspondence to Marta Pita-Vidal or Christian Kraglund Andersen.

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Pita-Vidal, M., Bargerbos, A., Žitko, R. et al. Direct manipulation of a superconducting spin qubit strongly coupled to a transmon qubit. Nat. Phys. 19, 1110–1115 (2023).

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