Numerical research on the response of Josephson junction with 0.14 THz nanosecond pulse radiation

Interaction between the high temperature (high-Tc) Josephson junctions and 0.14 THz nanosecond pulse has been numerically investigated in this paper. A general equivalent circuit based on resistively-shunted junction (RSJ) model was applied to simulate a typical high-Tc Josephson junction under the radiation of 0.14 THz narrow-band pulse with pulse duration of 2 ns. The varying ratio of phase difference of electron wave functions between the two sides of the junction, the current-voltage characteristics, and the voltage responses were determined at several specific times during the interaction. The Shapiro steps were clearly observed but distorted, and then the irradiation frequency was derived, coinciding with the simulated frequency. Also discussed were the effects of some parameters, including the pulse power, the normal resistance and the critical current of junction, on the current-voltage characteristics and the voltage responses. All the results showed that the high-Tc Josephson junctions probably could be used for the direct frequency measurements of narrow-band terahertz pulses under some specific conditions.