Abstract: An apparatus and method for implementing a compact and tunable microwave resonator using NbN kinetic inductance, comprising: a DC source, an attenuator, an oxygen-free copper cavity, a superconducting coil, a first-stage amplifier, a second-stage amplifier, a vector network analyzer and a control computer, a small-sized tunable resonator whose size is reduced by 10-20 times as compared with an ordinary thin film microwave resonator is implemented in a microwave frequency band by using high kinetic inductance of an ultra-thin NbN thin film in a superconducting state, the tunability of the resonator lies in that the ultra-thin NbN thin film serves as the LC resonance circuit, a dc-SQUID is connected to the end of the resonator, and a change in the external magnetic field causes a change in the equivalent inductance of the dc-SQUID, thereby changing the total inductance of the resonator and modulating the resonant frequency of the resonance circuit.

Abstract: An apparatus and method for implementing a compact and tunable microwave resonator using NbN kinetic inductance, comprising: a DC source, an attenuator, an oxygen-free copper cavity, a superconducting coil, a first-stage amplifier, a second-stage amplifier, a vector network analyzer and a control computer, a small-sized tunable resonator whose size is reduced by 10-20 times as compared with an ordinary thin film microwave resonator is implemented in a microwave frequency band by using high kinetic inductance of an ultra-thin NbN thin film in a superconducting state, the tunability of the resonator lies in that the ultra-thin NbN thin film serves as the LC resonance circuit, a dc-SQUID is connected to the end of the resonator, and a change in the external magnetic field causes a change in the equivalent inductance of the dc-SQUID, thereby changing the total inductance of the resonator and modulating the resonant frequency of the resonance circuit.