We investigate nonreciprocal scattering within the modes of a microwave frequency comb. Adjusting the pump frequencies, amplitudes, and phases of a Josephson parametric oscillator, we control constructive interference for the m⟶ℓ scattering processes, while concurrently achieving destructive interference for the inverse process ℓ⟶m. We outline the methodology for realizing nonreciprocity in the context of two-mode isolation and a three-mode circulation, which we extend to multiple modes. We find good agreement between the experiments and a linearized theoretical model. Nonreciprocal scattering expands the toolset for parametric control, with the potential to engineer alternative quantum correlations.
@article{arxiv.2501.09453,
title = {Non-reciprocal scattering in a microwave frequency comb},
author = {Christoph L. Bock and J. C. Rivera Hernández and Fabio Lingua and David B. Haviland},
journal= {arXiv preprint arXiv:2501.09453},
year = {2025}
}