Matthias Steffen, Martin Sandberg, et al.
Supercond Sci Technol
We have designed, fabricated, and tested a frequency-tunable high-Q superconducting resonator made from a niobium titanium nitride film. The frequency tunability is achieved by injecting a DC through a current-directing circuit into the nonlinear inductor whose kinetic inductance is current-dependent. We have demonstrated continuous tuning of the resonance frequency in a 180 MHz frequency range around 4.5 GHz while maintaining the high internal quality factor Q>180000. This device may serve as a tunable filter and find applications in superconducting quantum computing and measurement. It also provides a useful tool to study the nonlinear response of a superconductor. In addition, it may be developed into techniques for measurement of the complex impedance of a superconductor at its transition temperature and for readout of transition-edge sensors.
Matthias Steffen, Martin Sandberg, et al.
Supercond Sci Technol
Josephine B. Chang, Michael R. Vissers, et al.
Applied Physics Letters
Hanhee Paik, Antonio Mezzacapo, et al.
Physical Review Letters
Martin Sandberg, Emanuel Knill, et al.
Quantum Information Processing