MEASURING AMPLITUDE AND FREQUENCY CHARACTERISTICS OF KINETIC INDUCTANCE IN SUPERCONDUCTING FILMS

This research was performed using thin superconducting strips in the shape of tightly packed meanders made of niobium nitride (NbN) ultrathin superconducting strips about 100 nm wide, 5 nm thick and up to 100 µm long. The structures revealed the effect of high kinetic inductance at temperatures lower than the critical temperature. Consideration was given to the temperature dependence of LC-circuit resonant frequency where a highlyinductive superconducting meander was used as a source of L inductance and а chip capacitor as a source of C capacitance. Experimental data point to the fact that kinetic inductance depends on temperature, since there was a shift in the resonant frequency at temperatures lower than the critical one relative to the normal state. This is indicative to the fact that in such systems impedance is changed due to growing kinetic inductance during the transition to the superconducting state. This effect is of relevance both in applied and basic research. When using different superconducting detectors, kinetic inductance can exert a distinct effect on their response rate. In basic research developments, where the on-chip implementation of charge (current) stabilization is required, high frequency impedance of connecting circuits is very useful.