Physica C: Superconductivity and its Applications ( IF 1.3 ) Pub Date : 2021-07-27 , DOI: 10.1016/j.physc.2021.1353933 K. Harrabi 1, 2 , A. Mekki 1 , H. Bahlouli 1 , P. Mathieu 3
We have investigated the dynamics of dissipative states in NbTi superconducting thin films using electrical step pulse excitations on a sapphire substrate close to T. Excitation of a superconducting wire with a current pulse larger than the depairing critical current, I, gives rise to a non-equilibrium superconducting state. We identified two dissipative states, the hotspot (HS) and the phase slip center (PSC). Both are signaled by a voltage that emerges after a certain delay time t. We focused on the phase slip phenomenon in the vicinity of T and measured the dependence of the delay times on the value of the applied current pulse; these were fitted with the time-dependent Ginzburg-Landau (TDGL) theory due to Tinkham. The film thermal relaxation times were deduced for the phase slip center close to T for different samples. In addition, the temperatures at the center of the PSCs were estimated from the blackbody radiation model, and the results are consistent with the PSC formalism.
中文翻译:
使用接近 Tc 的电脉冲在超导 NbTi 细丝中获得的相滑中心温度
我们已经在接近 T 的蓝宝石衬底上使用电子步进脉冲激发研究了 NbTi 超导薄膜中耗散状态的动力学. 用大于失电临界电流 I 的电流脉冲激励超导线,产生非平衡超导状态。我们确定了两种耗散状态,即热点 (HS) 和相滑中心 (PSC)。两者都由在一定延迟时间 t 后出现的电压发出信号. 我们专注于 T 附近的相滑现象并测量延迟时间对所施加电流脉冲值的依赖性;由于 Tinkham,这些与时间相关的 Ginzburg-Landau (TDGL) 理论相吻合。对于接近 T 的相滑中心,推导出薄膜热弛豫时间对于不同的样品。此外,PSC 中心的温度是根据黑体辐射模型估计的,结果与 PSC 形式主义一致。