All-optical control of antiferromagnetic domains via an inverse optical magnetoelectric effect

TL;DR

This paper demonstrates a novel all-optical method to control antiferromagnetic domains using the inverse optical magnetoelectric effect in ferrotoroidic LiNiPO4, enabling nonvolatile, deterministic switching driven solely by light propagation direction.

Contribution

It introduces the inverse optical magnetoelectric effect as a new mechanism for manipulating antiferromagnetic order with light, distinct from traditional magneto-optical techniques.

Findings

Achieved nonvolatile, deterministic switching of antiferromagnetic domains.

Demonstrated control by reversing light propagation direction.

Established photon momentum coupling as a new control paradigm.

Abstract

Antiferromagnets are a promising platform for next-generation spintronics due to their ultrafast spin dynamics and robustness to external fields. All-optical control of antiferromagnetic order is essential to fully exploit their potential in energy-efficient and high-speed spintronic and memory applications. However, optical writing of antiferromagnetic domains remains a fundamental challenge, as conventional magneto-optical techniques rely on net magnetization, which is absent in antiferromagnets. In certain multiferroic antiferromagnets, the magnetic toroidal moment provides an additional degree of freedom through its inherent magnetoelectric coupling. This coupling at higher frequencies results in the optical magnetoelectric effect (OME), which manifests as a directional asymmetry in light propagation and enables optical probing of antiferromagnetic states. Here, we demonstrate all-optical writing of antiferromagnetic domains using the inverse optical magnetoelectric effect (IOME) in ferrotoroidic LiNiPO4. The writing process is nonvolatile, non-thermal, and deterministic, driven solely by reversing the light propagation direction. This directional control arises from a strong coupling between the photon linear momentum and the magnetic toroidal moment, enabling the repeatable switching between time-reversed domains with arbitrary light polarization. Our findings establish IOME as a distinct mechanism for manipulating antiferromagnetic order, opening a new paradigm in opto-magnetism driven by photon momentum.