发表机构
University of Salerno; INFN, Sezione di Napoli, Gruppo Collegato di Salerno; CNR-SPIN; QuantWare; University of Sannio（萨莱诺大学; 意大利国家核物理研究所，那不勒斯分部，萨莱诺协作组; 意大利国家研究委员会自旋物理中心; QuantWare公司; 萨尼奥大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究将两个串联约瑟夫森结系统约化为合成高透射率约瑟夫森元件，通过RCSJ方程对比验证其在低驱动频率下一致性良好，为超导电路应用提供定量动力学判据。
AI 中文摘要
当电容和电阻通道的电流可忽略时，两个串联的常规约瑟夫森结在静态极限下可复现具有可调透射率的单个有效弱连接的电流相位关系，因此该双结串联结构可被视为单个合成高透射率元件。本文研究在有限频率驱动且保留结的电阻和电容项的情况下，该映射在多大程度上仍然有效。我们将完整的电阻电容分流约瑟夫森（RCSJ）方程与具有可调透射率的有效合成元件进行比较，该元件保留了合成可调透射率的电流相位关系以及有效的电容和耗散项，从而将二阶自由度的双结系统约化为单个二阶自由度的系统。我们将所得的单元件动力学与完整双结系统在交流激发下的动力学进行比较，通过完整和有效电压波形之间的归一化均方根误差来量化一致性。在低驱动频率下发现了一个宽的低误差区域，而当驱动频率接近相关等离子体频率尺度且驱动幅度较大时，会出现明显偏差。这些结果为在超导电路中使用合成高透射率约瑟夫森元件的约化单元件描述提供了定量动力学判据。
英文摘要
Two conventional Josephson junctions connected in series can reproduce, in the static limit in which the currents through the capacitive and resistive channels are negligible, the current-phase relation of a single effective weak link with tunable transparency. Therefore, the two-junction series can be treated as a single synthetic high-transparency element. Here, we investigate to what extent this mapping remains valid under finite-frequency drive and retaining the junctions' resistive and capacitive terms. The full resistively and capacitively shunted junction equations are compared with an effective synthetic element with tunable transparency that retains the synthetic tunable-transparency current-phase relation together with effective capacitive and dissipative terms, thus reducing the two second order degree of freedom system to a single second order degree of freedom. The resulting single-element dynamics is compared with the complete two-junction system under ac excitation. The agreement is quantified through a normalized root-mean-square error between the full and effective voltage waveforms. A broad low-error region is found at low drive frequency, while pronounced deviations emerge as the drive frequency approaches the relevant plasma-frequency scale and at larger drive amplitudes. The results provide a quantitative dynamical criterion for using the reduced single-element description of a synthetic high-transparency Josephson element in superconducting circuits.
Comments5 pages, 2 figures. Submitted as a WOLTE17 contribution for consideration in the IEEE Trans. Appl. Supercond. Special Issue
