Cavity-Enhanced Optical Manipulation of Antiferromagnetic Magnon-Pairs

TL;DR

This paper proposes a method to control and generate squeezed magnon-pair states in antiferromagnets using cavity-enhanced optical manipulation, enabling new quantum information applications.

Contribution

It introduces a cavity-driven approach to produce and analyze steady and dynamic magnon-pair states, including squeezing, limit cycles, and chaos, in antiferromagnetic materials.

Findings

Squeezed magnon-pair states can be achieved with optical cavity control.

Different dynamical regimes (limit cycles, chaos) depend on drive detuning and power.

Critical power thresholds determine the transition to squeezing and other phases.

Abstract

The optical manipulation of magnon states in antiferromagnets (AFMs) holds significant potential for advancing AFM-based computing devices. In particular, two-magnon Raman scattering processes are known to generate entangled magnon-pairs with opposite momenta. We propose to harness the dynamical backaction of a driven optical cavity coupled to these processes, to obtain steady states of squeezed magnon-pairs, represented by squeezed Perelomov coherent states. The system's dynamics can be controlled by the strength and detuning of the optical drive and by the cavity losses. In the limit of a fast (or lossy) cavity, we obtain an effective equation of motion in the Perelomov representation, in terms of a light-induced frequency shift and a collective induced dissipation which sign can be controlled by the detuning of the drive. In the red-detuned regime, a critical power threshold defines a region where magnon-pair operators exhibit squeezing, a resource for quantum information, marked by distinct attractor points. Beyond this threshold, the system evolves to limit cycles of magnon-pairs. In contrast, for resonant and blue detuning regimes, the magnon-pair dynamics exhibit limit cycles and chaotic phases, respectively, for low and high pump powers. Observing strongly squeezed states, auto-oscillating limit cycles, and chaos in this platform presents promising opportunities for future quantum information processing, communication developments, and materials studies.