Asymmetric frequency conversion in nonlinear systems driven by a biharmonic pump

TL;DR

This paper introduces a new mechanism for asymmetric frequency conversion in nonlinear systems using a biharmonic pump, enabling nonreciprocal and efficient frequency conversion with potential practical implementation in Josephson junctions.

Contribution

It demonstrates how phase tuning of a biharmonic pump induces nonreciprocal frequency conversion, with a practical realization in Josephson junction systems.

Findings

Asymmetric frequency conversion depends on pump phase tuning.

Full directionality and efficiency are achievable with proper power distribution.

Practical implementation demonstrated in Josephson junction model.

Abstract

A novel mechanism of asymmetric frequency conversion is investigated in nonlinear dispersive devices driven parametrically with a biharmonic pump. When the relative phase between the first and second harmonics combined in a two-tone pump is appropriately tuned, nonreciprocal frequency conversion, either upward or downward, can occur. Full directionality and efficiency of the conversion process is possible, provided that the distribution of pump power over the harmonics is set correctly. While this asymmetric conversion effect is generic, we describe its practical realization in a model system consisting of a current-biased, resistively-shunted Josephson junction (RSJ). Here, the multiharmonic Josephson oscillations, generated internally from the static current bias, provide the pump drive.