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arXiv · 0802.0640

Quasiparticle relaxation in optically excited high-Q superconducting resonators

R. Barends·J. J. A. Baselmans·S. J. C. Yates·J. R. Gao·J. N. Hovenier·T. M. Klapwijk
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Abstract

The quasiparticle relaxation time in superconducting films has been measured as a function of temperature using the response of the complex conductivity to photon flux. For tantalum and aluminium, chosen for their difference in electron-phonon coupling strength, we find that at high temperatures the relaxation time increases with decreasing temperature, as expected for electron-phonon interaction. At low temperatures we find in both superconducting materials a saturation of the relaxation time, suggesting the presence of a second relaxation channel not due to electron-phonon interaction.

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R. Barends, J. J. A. Baselmans, S. J. C. Yates, J. R. Gao, J. N. Hovenier, T. M. Klapwijk. 2008-06-05. Quasiparticle relaxation in optically excited high-Q superconducting resonators. https://doi.org/10.1103/physrevlett.100.257002

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