Evidence of the disorder-independent electron-phonon scattering time in thin NbN films

Article

关键词: RESISTIVITY;    SUPERCONDUCTIVITY;    RELAXATION;    TRANSITION;    QUANTUM;    FIELD;   

DOI  :  10.1103/PhysRevB.107.054205

来源: SCIE

【 摘 要 】

We report on experimental study of the effect of disorder on electronic parameters and inelastic scattering mechanisms in ultrathin superconducting NbN films, which are commonly used in single-photon detectors. An increase in disorder in the studied 2.5-nm-thick NbN films characterized by Ioffe-Regel parameter from 6.3 to 1.6 is accompanied by a decrease in the critical temperature Tc from 11.5 to 3.4 K. By measuring magnetoconductance in the range from Tc to -3Tc, we extract the inelastic scattering rates of electrons, including electron-phonon (e-ph) scattering rate r-1e-ph. We observe that r-1e-ph and their temperature dependencies are insensitive to disorder that is not described by the existing models of the e-ph scattering in disordered metals. As temperature decreases, the temperature dependence of r-1e-ph varies from T3 to T2, which can be result of a decrease in the dimensionality of phonons involved in the e-ph scattering process. Our results call for further theoretical and experimental studies of the e-ph scattering in ultrathin disordered films.

【 授权许可】

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