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Fano Interference in Microwave Resonator Measurements

ORAL

Abstract

Resonator measurements are a simple but powerful tool to characterize a material’s microwave response. The losses of a resonant mode are quantified by its internal quality factor Qi, which can be extracted from the scattering coefficient in a microwave reflection or transmission measurement. Here we show that a systematic error on Qi arises from Fano interference of the signal with a background path. Limited knowledge of the interfering paths in a given setup translates into a range of uncertainty for Qi, which increases with the coupling coefficient. We experimentally illustrate the relevance of Fano interference in typical microwave resonator measurements and the associated pitfalls encountered in extracting Qi. On the other hand, we also show how to characterize and utilize the Fano interference to eliminate the systematic error.

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Presenters

  • Simon Günzler

    PHI, Karlsruhe Institute of Technology, Germany, IQMT and PHI, Karlsruhe Institute of Technology (KIT), Germany, Karlsruhe Institute of Technology (KIT), IQMT and PHI, Karlsruhe Institute of Technology, Karlsruhe Institute of Technology

Authors

  • Simon Günzler

    PHI, Karlsruhe Institute of Technology, Germany, IQMT and PHI, Karlsruhe Institute of Technology (KIT), Germany, Karlsruhe Institute of Technology (KIT), IQMT and PHI, Karlsruhe Institute of Technology, Karlsruhe Institute of Technology

  • Dennis Rieger

    PHI, Karlsruhe Institute of Technology, Germany, IQMT and PHI, Karlsruhe Institute of Technology (KIT), Germany, Karlsruhe Institute of Technology (KIT), Karlsruhe Institute of Technology, PHI, Karlsruhe Institute of Technology

  • Martin Spiecker

    PHI, Karlsruhe Institute of Technology, Germany, IQMT and PHI, Karlsruhe Institute of Technology (KIT), Germany, Karlsruhe Institute of Technology (KIT), IQMT and PHI, Karlsruhe Institute of Technology (KIT), IQMT and PHI, Karlsruhe Institute of Technology

  • Ameya Nambisan

    IQMT and PHI, Karlsruhe Institute of Technology

  • Wolfgang Wernsdorfer

    IQMT and PHI, Karlsruhe Institute of Technology, Germany, IQMT and PHI, Karlsruhe Institute of Technology (KIT), IQMT and PHI, Karlsruhe Institute of Technology (KIT), Germany, Karlsruhe Institute of Technology (KIT), IQMT and PHI, Karlsruhe Institute of Technology, Karlsruhe Institute of Technology

  • Ioan M Pop

    IQMT and PHI, Karlsruhe Institute of Technology, Germany, IQMT and PHI, Karlsruhe Institute of Technology (KIT), IQMT and PHI, Karlsruhe Institute of Technology (KIT), Germany, Karlsruhe Institute of Technology (KIT), IQMT and PHI, Karlsruhe Institute of Technology, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany