Unusual Nonlinear Dynamics Observed in NbN Superconducting Microwave Resonators
نویسندگان
چکیده
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 hypothesized as the main origin of the nonlinearities.
منابع مشابه
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...
متن کاملIntermodulation 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...
متن کاملExtreme 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...
متن کاملMicrowave Intermodulation in High-Tc Superconducting Microstrip Resonators
|We present experimental results on microwave intermodulation measurements on a High Tc Superconducting band-reject microstrip resonator which exhibits unconventional 2:1 intermodulation products. We discuss unusual features of this 2:1 behavior that are uncovered by detailed frequency swept and unbalanced power measurements. We also introduce a phenomenological theory which arises from a nonli...
متن کاملThermal instability and self-sustained modulation in superconducting NbN stripline resonators
We study theoretically and experimentally the response of a microwave superconducting stripline resonator, integrated with a microbridge, to a monochromatic injected signal. We find that there is a certain range of driving parameters in which a novel nonlinear phenomenon emerges, and self-sustained modulation of the reflected power off the resonator is generated by the resonator. A theoretical ...
متن کامل