Millimeter wave inducing subharmonic steps in the Tl2Ba2CaCu2O8 thin film bicrystal Josephson junction

Abstract The bicrystal Josephson junction (BJJ) was fabricated by patterning microbridge into Tl 2 Ba 2 CaCu 2 O 8 (Tl-2212) thin film grown epitaxially on the bicrystal SrTiO 3 (STO) substrate. The millimeter wave responses of BJJ were researched by experiment and numerical simulation. Shapiro steps and subharmonic steps were both observed in the current–voltage ( I – V ) curve at the liquid nitrogen temperature. In the resistive–capacitive–inductive shunted junction (RCLSJ) model, both of the Shapiro steps and subharmonic steps were reproduced with varying capacitances and inductances. The result of simulation has a good agreement with the experiment. The relative large capacitance and inductance correspond to distinct subharmonic steps.