Microwave Residual Surface Resistance of Superconductors

TL;DR

This paper compares two models explaining the microwave residual surface resistance in superconductors, showing they have similar predictions but differ in explaining sensitivity to sample history.

Contribution

It demonstrates that the phonon-generation and fluxoid models are essentially equivalent in predictions, but differ in their explanations of experimental sensitivities.

Findings

Both models agree with temperature and frequency dependence data.

Passow's phonon-generation model cannot explain sample preparation sensitivity.

Rabinowitz's fluxoid model accounts for sample history effects.

Abstract

Two distinct models account for the microwave residual surface resistance of superconducting cavities with equally good agreement with the measured temperature and frequency dependence. In presenting his phonon-generation model, Passow claimed that Rabinowitz' fluxoid power-loss model of residual resistance does not fit the experimental data, whereas his does. In fact, the two models have essentially the same temperature and frequency dependence. Furthermore, Passow's phonon-generation model cannot explain the observed sensitivity to details of sample preparation and history, while the fluxoid model can.