Electrical control of exchange spring in antiferromagnetic metals

TL;DR

This paper demonstrates a reversible electrical method using ionic liquids to control exchange springs in antiferromagnetic metals, enabling deeper and more stable manipulation of AFM spins for low-power spintronic devices.

Contribution

It introduces a novel ionic liquid-based electrical control technique for exchange springs in AFM metals, overcoming surface charge screening limitations.

Findings

Reversible electrical control of exchange spring in AFM metals.

Deeper modulation depth achieved in AFM metals up to 5 nm thickness.

Potential for low-power AFM spintronics applications.

Abstract

Manipulation of antiferromagnetic (AFM) spins by electrical means is on great demand to develop the AFM spintronics with low power consumption. In spite of the electrical modulation of insulated AFMs through coupling between their intrinsic ferroelectricity and antiferromagnetism, direct electrical control of AFM metals remains challenging due to the screening effect by the surface charge, and the manipulation is confined to a limited depth of atomic dimensions, which is insufficient to form a stable AFM exchange spring. In the present letter we primarily report a reversible electrical control of exchange spring in AFM metals, using an ionic liquid to exert a substantial electric-field effect. The exchange spring could transfer the force to the ferromagnet/antiferromagnet interface, enabling a deeper modulation depth in AFM metals. The manipulation of AFM moments by gate voltage is demonstrated in [Co/Pt]/IrMn model system and a single IrMn layer with the IrMn thickness up to 5 nm. Besides the fundamental significance of modulating the spin structures in metallic AFM via all-electrical fashion, the present finding would advance the development of low-power-consumption AFM spintronics.