In some implementations, a superconducting
integrated circuit has a tunable parallel-plate
capacitor, and a
magnetic field generator operable to apply a
magnetic field to the tunable parallel-plate
capacitor to tune a
capacitance of the tunable parallel-plate
capacitor. The tunable parallel-plate capacitor includes a first capacitor plate having a plane, a second capacitor plate having a plane, and a
dielectric interposed between the first capacitor plate and the second capacitor plate. The plane of the second capacitor plate is geometrically parallel to the plane of the first capacitor plate. In some implementations, a superconducting
integrated circuit has a tunable parallel-plate capacitor, and an
electric field generator operable to apply an
electric field to the tunable parallel-plate capacitor to tune a
capacitance of the tunable parallel-plate capacitor. The tunable parallel-plate capacitor includes a pair of capacitor plates, and a
dielectric interposed between the pair of plates.