Resistive state and charge imbalance waves in superconducting indium bridges with large cross section

We have investigated the Josephson behavior in indium microbridges with 2 µm thickness, 5–8 µm width, and 9–21 µm length. The resistive behavior of the bridges can be described by a dynamic model consisting of an ideal Josephson oscillator emitting charge imbalance waves into the adjacent superconductor. From the analogy between the charge imbalance wave equation and the telegraph equation a useful equivalent circuit is obtained, as pointed out recently by Kadin et al. The Josephson behavior in the different regimes of amplitude and frequency of the rf current superimposed upon the dc current is discussed.