Josephson switching device utilizing the quantum transitions in a superconducting quantum interference device loop

We propose a new type of Josephson switching device which utilizes quantum transitions in a superconducting quantum interference device (SQUID) loop. This device is driven by a DC bias current and RF magnetic field. The output voltage is determined by the transition rate and the AC-Josephson relationship. We investigate the desirable device parameters by simulation. Two parameters, the maximum step height and the overlapped current region for the 0th and 1st steps, are plotted as functions of frequency and power of the RF-field activation. We also derive the relationship between the gain and device parameters. The analytical relationship is in good agreement with the numerical results. Besides the simple switching operation, a flip-flop operation is also successfully simulated. The results indicate that the device with appropriate parameters is suitable for switching applications.