A deep understanding of the quasiparticle inelastic scattering rate in superconducting materials is beneficial for the further development of ultrasensitive and rapid superconducting detectors. From the flux flow instability in current–voltage characteristics of NbN superconducting films, we have derived the critical vortex velocity (ʋ*) and quasiparticle inelastic scattering time (τ_E) of the 10- and 15-nm-thick NbN films at different magnetic fields and temperatures within the framework of the Larkin–Ovchinnikov model. The critical vortex velocity drove the transition from the power law ʋ* ∝ B^−1/2 dependent to field-independent behavior where the nonequilibrium quasiparticles are uniformly distributed. The inelastic scattering time of quasiparticles obeys T⁻ⁿ temperature dependence, where the exponents are 2.5 and 2.3 for the 10 and 15-nm-thick NbN films, respectively. As the thickness of the film decreases from 15 to 10 nm, a reduction of τ_E from 88 to 12 ps is observed at 8 K. Moreover, the small value of τ_E for ultra-thin films can be associated with the low-average value of the superconducting gap, which is precisely what the detector needs.

深入了解超导材料中的准粒子非弹性散射速率，对于进一步开发超灵敏，快速的超导探测器是有好处的。从在的NbN超导膜的电流-电压特性的磁通流动不稳定性，我们已得出的临界涡流速度（ʋ* ）和准粒子非弹性散射时间（τ _Ë在不同磁性的10-和15-nm厚的NbN膜） Larkin-Ovchinnikov模型的框架内的温度场和温度。临界涡旋速度推动了幂定律ʋ * ∝ B ^-1/2的转变取决于非平衡准粒子均匀分布的场无关行为。准粒子的非弹性散射时间服从T ^{- n}温度依赖性，其中10和15 nm厚的NbN薄膜的指数分别为2.5和2.3。随着膜的厚度减小15〜10纳米，减少了τ _ë从88到12个ps的在8 K.观察此外，小值τ _Ë为超薄膜可以与低平均相关联超导间隙的值，正是检测器需要的值。