The continuous development of superconducting electronics is encouraging several studies on hybrid Josephson junctions (JJs) based on superconductor-ferromagnet-superconductor (SFS) heterostructures, as either spintronic devices or switchable elements in quantum and classical circuits. Recent experimental evidence of macroscopic quantum tunneling and of an incomplete 0-$\pi$ transition in tunnel-ferromagnetic spin-filter JJs could also enhance the capabilities of SFS JJs as active elements. Here, we provide a self-consistent electrodynamic characterization of $\mathrm{Nb}\mathrm{N}$/$\mathrm{Gd}\mathrm{N}$/$\mathrm{Nb}\mathrm{N}$ spin-filter JJs as a function of the barrier thickness, disentangling the high-frequency dissipation effects due to the environment from the intrinsic low-frequency dissipation processes. The fitting of the $I$-$V$ characteristics at 4.2 K and at 300 mK by using the tunnel-junction-microscopic model allows us to determine the subgap resistance $R_{\mathrm{sg}}$, the quality factor $Q$, and the junction capacitance $C$. These results provide the scaling behavior of the electrodynamic parameters as a function of the barrier thickness, which represents a fundamental step for the feasibility of tunnel-ferromagnetic JJs as active elements in quantum and classical circuits, and are of general interest for tunnel junctions other than conventional SIS JJs.

中文翻译：

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高自旋极化隧道约瑟夫森结的电动力学

超导电子学的不断发展鼓舞了对基于超导体-铁磁体-超导体（SFS）异质结构的混合约瑟夫森结（JJs）的多项研究，这些结既可以用作自旋电子器件，也可以用作量子和经典电路中的可开关元件。宏观量子隧穿和不完全0-的最新实验证据$\pi$隧道铁磁自旋滤波器JJ的跃迁也可以增强SFS JJ作为有源元件的能力。在这里，我们提供了一个自洽的电动特性$铌\mathrm{ñ}$/$d\mathrm{ñ}$/$铌\mathrm{ñ}$自旋滤波器的JJs是势垒厚度的函数，从而消除了由环境引起的高频耗散效应与固有的低频耗散过程的关系。的拟合$\mathrm{一世}$--$V$ 通过使用隧道结微观模型在4.2 K和300 mK下的特性可以确定亚间隙电阻 ${\mathrm{[R}}_g$，品质因数 $问$，以及结电容 $C$。这些结果提供了电动力学参数随势垒厚度变化的缩放行为，这代表了将隧道铁磁JJ用作量子和经典电路中的有源元件的可行性的基本步骤，并且对于除隧道结以外的其他隧道结具有普遍意义常规SIS JJ。