论文标题
在薄NBN膜中，与疾病无关的电子散射时间的证据
Evidence of the disorder-independent electron-phonon scattering time in thin NbN films
论文作者
论文摘要
我们报告了障碍对超薄超导NBN膜中电子参数和非弹性散射机制的影响的实验研究，该膜通常用于单光子检测器中。 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 $T_c$ from 11.5 K to 3.4 K. By measuring magnetoconductance in the range from $T_c$ to $\sim3T_c$, we extract the inelastic scattering rates of electrons, including electron-phonon (e-ph) scattering费率$τ_{e-ph}^{ - 1} $。我们观察到$τ_{e-ph}^{ - 1} $及其温度依赖性对疾病不敏感，而无序金属中的E-PH散射模型未描述，这可能是由于存在弱小的金属晶粒。随着温度的降低，温度依赖性$τ_{e-ph}^{ - 1} $从$ t^3 $变为$ t^2 $，这可能是由于E-PH散射中涉及的声子的尺寸降低。超薄NBN膜的材料参数的值可用于优化基于NBN的电子设备的性能。
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 $T_c$ from 11.5 K to 3.4 K. By measuring magnetoconductance in the range from $T_c$ to $\sim3T_c$, we extract the inelastic scattering rates of electrons, including electron-phonon (e-ph) scattering rates $τ_{e-ph}^{-1}$. We observe that $τ_{e-ph}^{-1}$ and their temperature dependencies are insensitive to disorder that is not described by the existing models of the e-ph scattering in disordered metals and can be due to the presence of weakly disordered metal grains. As the temperature decreases the temperature dependence $τ_{e-ph}^{-1}$ changes from $T^3$ to $T^2$, which can be result of a decrease in the dimension of the phonons involved in the e-ph scattering. The obtained values of material parameters of ultrathin NbN films can be useful for optimization of performance of NbN-based electronic devices.
