Dissipation-induced nonreciprocal magnon blockade in a magnon-based hybrid system

TL;DR

This paper proposes a practical nonreciprocal magnonic device that leverages dissipation and coherent coupling to achieve single-magnon level nonreciprocal behavior, advancing quantum magnonics.

Contribution

It introduces a novel hybrid system design that combines coherent and dissipative interactions to realize nonreciprocal magnon blockade at the quantum level.

Findings

Demonstrates direction-dependent magnon blockade via correlation functions

Shows the interplay of virtual photon-mediated coupling and dissipation induces nonreciprocity

Provides a feasible experimental scheme for quantum magnonic devices

Abstract

We propose an experimentally realizable nonreciprocal magnonic device at the single-magnon level by exploiting magnon blockade in a magnon-based hybrid system. The coherent qubit-magnon coupling, mediated by virtual photons in a microwave cavity, leads to the energy-level anharmonicity of the composite modes. In contrast, the corresponding dissipative counterpart, induced by traveling microwaves in a waveguide, yields inhomogeneous broadenings of the energy levels. As a result, the cooperative effects of these two kinds of interactions give rise to the emergence of the direction-dependent magnon blockade. We show that this can be demonstrated by studying the equal-time second-order correlation function of the magnon mode. Our study opens an avenue to engineer nonreciprocal magnonic devices in the quantum regime involving only a small number of magnons.