Non-reciprocal scattering in a microwave frequency comb

TL;DR

This paper demonstrates controllable nonreciprocal scattering in a microwave frequency comb using a Josephson parametric oscillator, enabling directional control of microwave signals with potential applications in quantum information processing.

Contribution

It introduces a method to achieve nonreciprocal scattering in a microwave frequency comb by tuning pump parameters, extending nonreciprocal control to multiple modes.

Findings

Good agreement between experiment and theory

Controlled nonreciprocity via interference effects

Potential for engineering quantum correlations

Abstract

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 $m \longrightarrow \ell$ scattering processes, while concurrently achieving destructive interference for the inverse process $\ell \longrightarrow m$. 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.