Chiral cavity-magnonic system for the unidirectional photon blockade

TL;DR

This paper introduces a chiral cavity-magnon system enabling directional single-photon emission with robustness against imperfections, controlled by magnetic field reversal, advancing quantum communication technologies.

Contribution

It presents a novel scheme for unidirectional photon blockade using a chiral cavity-magnon system with robustness to nonidealities.

Findings

Achieves directional single-photon emission controlled by magnetic field.

Demonstrates robustness of photon blockade against coupling imperfections.

Shows potential for integrated quantum photonic devices.

Abstract

We propose an scheme for directional single-photon source based on a chiral cavity-magnon system. In this system, the magnon mode in a single-crystal yttrium iron garnet (YIG) sphere is coupled to only one of two rotating microwave modes in the torus-shaped microwave cavity. When two-photon drives are applied to both ports of the waveguide, the chiral cavity-magnon coupling leads to an unconventional photon blockade in one propagation direction, resulting in directional single-photon emission. The emission direction of the single-photon source can be controlled by reversing the biased magnetic field. Furthermore, we further examine the effects of imperfect chiral cavity-magnon coupling and the coupling between the two cavity modes on the photon blockade behavior. The results show that the system retains robustness in the presence of these nonideal factors, and the unidirectional photon blockade effect remains clearly preserved.