论文标题
SNS连接的动力I-V特性
Dynamical I-V Characteristics of SNS Junctions
论文作者
论文摘要
我们已经通过测量其电压/电流特性，同时应用AC电流偏置在1-200 MHz的范围内，探测了超导弱连接的Josephson临界电流的开关动力学。两个NB储层之间的弱连接是由高于其临界温度的介观Al线形成的。我们观察到动态相变是交流电流频率和振幅的函数。尽管在低频率下，标准Kramers理论很好地描述了当前偏差驱动的过渡，但在高频上，开关直方图变得滞后，并且比热波动预期的要窄得多。两个机制之间的交叉频率是由正常金属中电子 - 光子相互作用速率设置的。
We have probed the switching dynamics of the Josephson critical current of a superconducting weak link by measuring its voltage/current characteristics while applying an ac current bias in the range 1-200 MHz. The weak link between two Nb reservoirs is formed by an mesoscopic Al wire above its critical temperature. We observe a dynamical phase transition as a function of the frequency and amplitude of the ac current. While at low frequency the transition driven by increasing the current bias is well described by the standard Kramers theory, at high frequency the switching histograms become hysteretic and much narrower than expected by thermal fluctuations. The crossover frequency between the two regimes is set by the electron-phonon interaction rate in the normal metal.
