Measurement Results of the Superconducting-Ferromagnetic Transistor

Ivan P. Nevirkovets, Takafumi Kojima, Yoshinori Uzawa, Oleg A. Mukhanov

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations


We report on the measurement results of the superconducting-ferromagnetic transistors (SFTs) made at Northwestern University and Hypres, Inc. [IEEE Trans. Appl. Supercond. vol. 24, 1800506 (2014); vol. 25, 1800705 (2015)]. SFT is a multi-terminal device with the SIS'FIFS structure (where S, I, and F denote a superconductor, an insulator, and a ferromagnetic material, respectively) exploiting intense quasiparticle injection in order to modify the non-linear I-V curve of a superconducting tunnel junction. Potentially, SFT is capable of providing voltage, current and power amplification while having good input/output isolation. We characterized the devices at frequencies up to 5 MHz at 4 K. Our setup did not allow for accurate measurement of the voltage gain of low-impedance SFT devices because of contribution of resistance of the bias-T connected in series with the SFT. Nevertheless we observed a voltage gain above unity for some measurement configurations. It is very interesting that we confirmed that the isolation between the input and output of the device is quite good. We suggest that further improvement of the SFT device parameters is possible in optimized devices, so that the device potentially may serve as a preamplifier for readout of output signals of cryogenic detectors and be useful as an element of other superconductor-based circuits.

Original languageEnglish (US)
Title of host publicationISEC 2019 - International Superconductive Electronics Conference
PublisherInstitute of Electrical and Electronics Engineers Inc.
ISBN (Electronic)9781728111964
StatePublished - Jul 2019
Event17th IEEE International Superconductive Electronics Conference, ISEC 2019 - Riverside, United States
Duration: Jul 28 2019Aug 1 2019

Publication series

NameISEC 2019 - International Superconductive Electronics Conference


Conference17th IEEE International Superconductive Electronics Conference, ISEC 2019
Country/TerritoryUnited States


  • Josephson effect
  • superconducting electronics
  • superconducting-ferromagnetic transistor
  • superconductivity
  • tunneling effect

ASJC Scopus subject areas

  • Fluid Flow and Transfer Processes
  • Hardware and Architecture
  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials


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