DC-powered broadband quantum-limited amplifiers

ORAL

Abstract

Fast, high-fidelity readout of superconducting qubit states is essential for fault-tolerant quantum computing and requires quantum-limited amplifiers, typically relying on down-conversion of microwave pump tone. However, generating, routing, and filtering this pump tone demands extensive hardware resources, hindering scalability. While traditional DC-powered amplifiers simplify system design, they have historically introduced excessive noise, compromising qubit state measurements.

In this talk, we present experimental advances in our DC-powered inelastic Cooper-pair tunneling amplifiers (ICTAs), addressing these challenges. Leveraging a custom semiclassical simulator, we demonstrate predictable, high-performance amplifiers with multi-GHz bandwidth, 15 dB gain, and input 1 dB compression points around -110 dBm. Our streamlined design, utilizing a single SQUID, achieves quantum-limited performance, paving the way for scalable, low-noise qubit readout in next-generation quantum computing architectures.

*The authors acknowledge financial support from the Natural Sciences and Engineering Research Council of Canada (NSERC) through grants RGPIN-2025-06130 and ALLRP 565748-22 and from the Qu\'{e}bec government through Prompt Qu\'{e}bec grant 05\_AQ22.001-V3.

Presenters

  • Naveen Nehra

    • Universite de Sherbrooke

Authors

  • Naveen Nehra

    • Universite de Sherbrooke
  • nicolas bourlet

    • Université de Sherbrooke
  • Ulrich Martel

    • Université de Sherbrooke
  • Max Hofheinz

    • Université de Sherbrooke