(DARPA) Quantum-Limited Measurement as a Tool for Entanglement in Superconducting Circuits

Abstract

Under the QuEST program the McDermott developed a variant of the dc SQUID that is optimized for amplification of microwave frequency signals. Here the gain element is more properly termed a Superconducting Low-inductance Undulatory Galvanometer (SLUG) as the input signal is injected directly into the loop inductance as a current. The microwave SLUG amplifier has achieved system added noise less than one quantum at 6 GHz, and demonstrated improvement in single-shot cQED qubit measurement fidelity from 60% (with a low-noise HEMT alone) to 99% in 600 ns. The SLUG microwave amplifier is an extremely promising readout technology for scalable superconducting surface codes due to its simple dc biasing requirements, large instantaneous bandwidth, high saturation power, and intrinsic reciprocity.

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Document Details

Document Type
Technical Report
Publication Date
Aug 29, 2013
Accession Number
ADA590769

Entities

People

  • Robert Mcdermott

Organizations

  • University of Wisconsin–Madison

Tags

DTIC Thesaurus Topics

  • Air Force Research Laboratories
  • Amplifiers
  • Bandwidth
  • Detection
  • Detectors
  • Electron Beam Lithography
  • Frequency
  • Josephson Junctions
  • Low Noise
  • Low Noise Amplifiers
  • Magnetometers
  • Measurement
  • Microwave Amplifiers
  • Microwave Frequency
  • Oscillators
  • Quantum Optics
  • Simulations

Fields of Study

  • Physics

Readers

  • Electronics Engineering
  • Quantum Dot Semiconductor Device Photonics and Graphene Optoelectronic Materials and THz Physics.
  • Superconducting Magnet Technology

Technology Areas

  • Quantum Computing