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DC-powered broadband quantum-limited microwave amplifier

N. Nehra*, N. Bourlet, A.H. Esmaeili, B. Monge, F. Cyrenne-Bergeron, A. Paquette, M. Arabmohammadi, A. Rogalle, Y. Lapointe et al.

M. Hofheinz

  • *Contact author: nn.iitr@gmail.com
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Phys. Rev. Applied 25, 064009 – Published 2 June, 2026

DOI: https://doi.org/10.1103/c4zz-pbk4

Abstract

Fast, high-fidelity, single-shot readout of superconducting qubits in quantum processors demands quantum-limited amplifiers to preserve the optimal signal-to-noise ratio. Typically, quantum-limited amplification is achieved with parametric down-conversion of a strong pump tone, which imposes significant hardware overhead and severely limits scalability. Here, we demonstrate the first dc-powered broadband amplifier operating within 0.2 photons of the quantum limit. Our impedance-engineered inelastic Cooper-pair tunneling amplifier (ICTA)—a voltage-biased superconducting quantum interference device in which Cooper pairs tunnel inelastically by emitting signal-idler photon pairs—operates in reflection, delivering 13 dB of average gain across a 3.5-GHz bandwidth in a single stage. Semiclassical simulations accurately predict the gain and saturation power, enabling further design improvements. By eliminating the pump-tone infrastructure, the broadband ICTA promises to dramatically reduce the hardware complexity of quantum-limited amplification in superconducting quantum processors.

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References (25)

  1. D. Sank et al., Measurement-induced state transitions in a superconducting qubit: Beyond the rotating wave approximation, Phys. Rev. Lett. 117, 190503 (2016).
  2. M. Khezri, A. Opremcak, Z. Chen, K. C. Miao, M. McEwen, A. Bengtsson, T. White, O. Naaman, D. Sank, A. N. Korotkov, Y. Chen, and V. Smelyanskiy, Measurement-induced state transitions in a superconducting qubit: Within the rotating-wave approximation, Phys. Rev. Appl. 20, 054008 (2023).
  3. M. A. Castellanos-Beltran, K. D. Irwin, G. C. Hilton, L. R. Vale, and K. W. Lehnert, Amplification and squeezing of quantum noise with a tunable Josephson metamaterial, Nat. Phys. 4, 929 (2008).
  4. N. Bergeal, F. Schackert, M. Metcalfe, R. Vijay, V. E. Manucharyan, L. Frunzio, D. E. Prober, R. J. Schoelkopf, S. M. Girvin, and M. H. Devoret, Phase-preserving amplification near the quantum limit with a Josephson ring modulator, Nature 465, 64 (2010).
  5. J. Y. Mutus, T. C. White, R. Barends, Y. Chen, Z. Chen, B. Chiaro, A. Dunsworth, E. Jeffrey, J. Kelly, A. Megrant, C. Neill, P. J. J. O’Malley, P. Roushan, D. Sank, A. Vainsencher, J. Wenner, K. M. Sundqvist, A. N. Cleland, and J. M. Martinis, Strong environmental coupling in a Josephson parametric amplifier, Appl. Phys. Lett. 104, 263513 (2014).
  6. T. Roy, S. Kundu, M. Chand, A. M. Vadiraj, A. Ranadive, N. Nehra, M. P. Patankar, J. Aumentado, A. A. Clerk, and R. Vijay, Broadband parametric amplification with impedance engineering: Beyond the gain-bandwidth product, Appl. Phys. Lett. 107, 262601 (2015).
  7. O. Naaman, D. G. Ferguson, A. Marakov, M. Khalil, W. F. Koehl, and R. J. Epstein, in 2019 IEEE MTT-S International Microwave Symposium (IMS) (2019), pp. 259–262.
  8. T. White et al., Readout of a quantum processor with high dynamic range Josephson parametric amplifiers, Appl. Phys. Lett. 122, 014001 (2023).
  9. O. Yaakobi, L. Friedland, C. Macklin, and I. Siddiqi, Parametric amplification in Josephson junction embedded transmission lines, Phys. Rev. B 87, 144301 (2013).
  10. C. Macklin, K. O’Brien, D. Hover, M. E. Schwartz, V. Bolkhovsky, X. Zhang, W. D. Oliver, and I. Siddiqi, A near–quantum-limited Josephson traveling-wave parametric amplifier, Science 350, 307 (2015).
  11. A. Ranadive, M. Esposito, L. Planat, E. Bonet, C. Naud, O. Buisson, W. Guichard, and N. Roch, Kerr reversal in Josephson meta-material and traveling wave parametric amplification, Nat. Commun. 13, 1737 (2022).
  12. E. Jeffrey, D. Sank, J. Y. Mutus, T. C. White, J. Kelly, R. Barends, Y. Chen, Z. Chen, B. Chiaro, A. Dunsworth, A. Megrant, P. J. J. O’Malley, C. Neill, P. Roushan, A. Vainsencher, J. Wenner, A. N. Cleland, and J. M. Martinis, Fast accurate state measurement with superconducting qubits, Phys. Rev. Lett. 112, 190504 (2014).
  13. J. Heinsoo, C. K. Andersen, A. Remm, S. Krinner, T. Walter, Y. Salathé, S. Gasparinetti, J.-C. Besse, A. Potočnik, A. Wallraff, and C. Eichler, Rapid high-fidelity multiplexed readout of superconducting qubits, Phys. Rev. Appl. 10, 034040 (2018).
  14. P. A. Spring, L. Milanovic, Y. Sunada, S. Wang, A. F. van Loo, S. Tamate, and Y. Nakamura, Fast multiplexed superconducting-qubit readout with intrinsic purcell filtering using a multiconductor transmission line, PRX Quantum 6, 020345 (2025).
  15. C. Mori, V. Milchakov, F. D’Esposito, L. Ruela, S. Kumar, V. N. Suresh, W. Ardati, D. Nicolas, Q. Ficheux, N. Roch, T. Ramos, and O. Buisson, High-power readout of a transmon qubit using a nonlinear coupling, arXiv:2507.03642.
  16. D. Hover, Y.-F. Chen, G. J. Ribeill, S. Zhu, S. Sendelbach, and R. McDermott, Superconducting low-inductance undulatory galvanometer microwave amplifier, Appl. Phys. Lett. 100, 063503 (2012).
  17. P. Lähteenmäki, V. Vesterinen, J. Hassel, H. Seppä, and P. Hakonen, Josephson junction microwave amplifier in self-organized noise compression mode, Sci. Rep. 2, 276 (2012).
  18. S. Jebari, F. Blanchet, A. Grimm, D. Hazra, R. Albert, P. Joyez, D. Vion, D. Estève, F. Portier, and M. Hofheinz, Near-quantum-limited amplification from inelastic Cooper-pair tunnelling, Nature Electronics 1, 223 (2018).
  19. U. Martel, R. Albert, F. Blanchet, J. Griesmar, G. Ouellet, H. Therrien, N. Nehra, N. Bourlet, A. Peugeot, and M. Hofheinz, Influence of bias-voltage noise on the inelastic Cooper-pair tunneling amplifier (ICTA), Appl. Phys. Lett. 126, 074001 (2025).
  20. G.-L. Ingold and Y. V. Nazarov, in Single Charge Tunneling: Coulomb Blockade Phenomena in Nanostructures, NATO ASI Series B, Vol. 294, edited by H. Grabert and M. H. Devoret (Plenum, New York, 1992), Chap. 2, pp. 21–107.
  21. M. Hofheinz, F. Portier, Q. Baudouin, P. Joyez, D. Vion, P. Bertet, P. Roche, and D. Esteve, Bright side of the Coulomb blockade, Phys. Rev. Lett. 106, 217005 (2011).
  22. O. Naaman and J. Aumentado, Synthesis of parametrically coupled networks, PRX Quantum 3, 020201 (2022).
  23. L. Danner, C. Padurariu, J. Ankerhold, and B. Kubala, Injection locking and synchronization in Josephson photonics devices, Phys. Rev. B 104, 054517 (2021).
  24. A. Paquette, J. Griesmar, G. Lavoie, R. Albert, F. Blanchet, A. Grimm, U. Martel, and M. Hofheinz, Absorptive filters for quantum circuits: Efficient fabrication and cryogenic power handling, Appl. Phys. Lett. 121, 124001 (2022).
  25. C. Rapp, in Proc. Second European Conference on Satellite Communications, Liege, Belgium, Oct. 1991 (1991), p. 179.

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Phys. Rev. Applied 25, 064009– Published 2 June, 2026
  • Received 24 December 2025
  • Revised 3 February 2026
  • Accepted 27 April 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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