Networks of nonlinear superconducting transmission line resonators

Nonlinear dynamics in the resonance line shape of NbN superconducting resonators

We report on unusual nonlinear dynamics observed in the resonance response of NbN superconducting microwave resonators. The nonlinear dynamics which occurs at relatively low input powers 2–4 orders of magnitude lower than Nb includes among others, jumps in the resonance line shape, hysteresis loops changing direction, and resonance frequency shift. These effects are measured herein using varyin...

Intermodulation gain in nonlinear NbN superconducting microwave resonators

We report the measurement of intermodulation gain greater than unity in NbN superconducting stripline resonators. In the intermodulation measurements we inject two unequal tones into the oscillator—the pump and signal—both lying within the resonance band. At the onset of instability of the reflected pump we obtain a simultaneous gain of both the idler and the reflected signal. The measured gain...

Unusual Nonlinear Dynamics Observed in NbN Superconducting Microwave Resonators

We report on some unusual nonlinear dynamics observed in several NbN superconducting stripline microwave resonators. Among the nonlinear effects observed: abrupt bifurcations within the resonance lineshape, hysteretic behavior, hysteresis loops changing direction, resonance shift and critical coupling. Weak links forming at the boundaries of the columnar structure of the NbN films are hypothesi...

Extreme nonlinear phenomena in NbN superconducting stripline resonators

We study giant nonlinear phenomena that emerge near a bifurcation threshold (BT) in a microwave superconducting stripline resonator. Above the BT the system becomes astable and self-sustained modulation of the reflected power off the resonator occurs. The giant nonlinearity manifests itself in an extremely high intermodulation gain, accompanied by a very strong noise squeezing and period doubli...

Tunable Superconducting Split Ring Resonators