Tripartite high-dimensional magnon-photon entanglement in PT -symmetry broken phases of a non-Hermitian hybrid system

TL;DR

This paper investigates a non-Hermitian hybrid magnon-photon system with PT-symmetry phases, demonstrating the generation of robust tripartite high-dimensional entangled states in PT-broken phases, and proposes a circuit simulation method.

Contribution

It introduces a non-Hermitian magnon-circuit-QED model with PT-symmetry phases and shows how to generate stable high-dimensional entanglement in PT-broken phases.

Findings

Tripartite high-dimensional entangled states are generated in PT-broken phases.

Entangled states are robust against dissipation and independent of initial states.

Proposed simulation using an equivalent LCR circuit.

Abstract

Hybrid systems that combine spin ensembles and superconducting circuits provide a promising platform for implementing quantum information processing. We propose a non-Hermitian magnoncircuit-QED hybrid model consisting of two cavities and an yttrium iron garnet (YIG) sphere placed in one of the cavities. Abundant exceptional points (EPs), parity-time (PT )-symmetry phases and PT -symmetry broken phases are investigated in the parameter space. Tripartite highdimensional entangled states can be generated steadily among modes of the magnon and photons in PT -symmetry broken phases, corresponding to which the stable quantum coherence exists. Results show that the tripartite high-dimensional entangled state is robust against the dissipation of hybrid system, independent of a certain initial state, and insensitive to the fluctuation of magnonphoton coupling. Further, we propose to simulate the hybrid model with an equivalent LCR circuit. This work may provide prospects for realizing multipartite high-dimensional entangled states in the magnon-circuit-QED hybrid system.