Remote generation of magnon Schr\"{o}dinger cat state via magnon-photon entanglement

TL;DR

This paper proposes a method to remotely generate magnon Schr"{o}dinger cat states using entangled magnon-photon systems and local optical operations, achieving high fidelity and large size suitable for quantum tech applications.

Contribution

It introduces a novel approach for remote preparation of magnon cat states via pulsed optomagnonic interactions and local non-Gaussian optical operations, with analysis of experimental imperfections.

Findings

High-fidelity magnon cat states generated with feasible parameters

Large-sized cat states suitable for quantum applications

Estimated lifetime of magnon cat states around 1 microsecond

Abstract

Magnon cat state represents a macroscopic quantum superposition of collective magnetic excitations of large number spins that not only provides fundamental tests of macroscopic quantum effects but also finds applications in quantum metrology and quantum computation. In particular, remote generation and manipulation of Schr\"{o}dinger cat states are particularly interesting for the development of long-distance and large-scale quantum information processing. Here, we propose an approach to remotely prepare magnon even/odd cat states by performing local non-Gaussian operations on the optical mode that is entangled with magnon mode through pulsed optomagnonic interaction. By evaluating key properties of the resulting cat states, we show that for experimentally feasible parameters they are generated with both high fidelity and nonclassicality, and with a size large enough to be useful for quantum technologies. Furthermore, the effects of experimental imperfections such as the error of projective measurements and dark count when performing single-photon operations have been discussed, where the lifetime of the created magnon cat states is expected to be $t\sim1\,\mu$s.