Nondegenerate Parametric Resonance in a Tunable Superconducting Cavity
Journal article, 2017

We develop a theory for nondegenerate parametric resonance in a tunable superconducting cavity. We focus on nonlinear effects that are caused by nonlinear Josephson elements connected to the cavity. We analyze parametric amplification in a strong nonlinear regime at the parametric-instability threshold, and we calculate maximum gain values. Above the threshold, in the parametric-oscillator regime, the cavity linear response diverges at the oscillator frequency at all pump strengths. We show that this divergence is related to the continuous degeneracy of the free oscillator state with respect to the phase. Applying on-resonance input lifts the degeneracy and removes the divergence. We also investigate quantum noise squeezing. It is shown that in the strong amplification regime, the noise undergoes four-mode squeezing, and that, in this regime, the output signal-to-noise ratio can significantly exceed the input value. We also analyze the intermode frequency conversion and identify the parameters at which full conversion is achieved.

SQUID

Superconductivity

Quantum-Noise

Amplification

Quantum Information

Quantum entanglement

Author

Waltraut Wustmann

Chalmers, Microtechnology and Nanoscience (MC2), Applied Quantum Physics

Vitaly Shumeiko

Chalmers, Microtechnology and Nanoscience (MC2), Applied Quantum Physics

Physical Review Applied

2331-7019 (eISSN)

Vol. 8 2 024018

Subject Categories

Other Physics Topics

DOI

10.1103/PhysRevApplied.8.024018

More information

Latest update

4/5/2022 2