Demonstration of a tunable non-Hermitian nonlinear microwave dimer

Area of Science:

• Photonics and Microwave Engineering
• Non-Hermitian and Nonlinear Dynamics

Background:

• Controlling non-reciprocity in engineered photonic structures is crucial for scientific and engineering advancements.
• Non-Hermitian and nonlinear dynamics offer novel pathways for manipulating wave propagation.

Purpose of the Study:

• To introduce a tunable, non-Hermitian, nonlinear microwave dimer for precise phase-non-reciprocal hopping.
• To demonstrate control over amplitude and phase in forward and backward signal paths.

Main Methods:

• Utilized three-dimensional microwave cavities, unidirectional amplifiers, digital attenuators, and a digital phase shifter.
• Employed theoretical and numerical analysis to model system dynamics.
• Investigated parameter regimes with gain exceeding inherent loss.

Main Results:

• Successfully modeled and reproduced weak-drive transmission spectra.
• Quantitatively reproduced self-sustained limit cycle amplitude and frequency.
• Observed and modeled phase locking synchronization between limit cycles and external tones.

Conclusions:

• The developed microwave dimer precisely implements phase-non-reciprocal hopping dynamics.
• The system offers tunable control over signal propagation, applicable to various fields.
• Results provide insight into non-Hermitian and nonlinear dynamics interplay.