Nonvolatile Electric Control of Antiferromagnetic States on Nanosecond Timescales

Electrical manipulation of antiferromagnetic (AFM) states, a cornerstone of AFM spintronics, is a great challenge, requiring novel material platforms. Here we report the full control over AFM states by voltage pulses in the insulating <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msub><a:mtext>Co</a:mtext><a:mn>3</a:mn></a:msub><a:msub><a:mi mathvariant="normal">O</a:mi><a:mn>4</a:mn></a:msub></a:math> spinel well below its Néel temperature. We show that the strong linear magnetoelectric effect is fully governed by the orientation of the Néel vector. As a unique feature of <d:math xmlns:d="http://www.w3.org/1998/Math/MathML" display="inline"><d:msub><d:mtext>Co</d:mtext><d:mn>3</d:mn></d:msub><d:msub><d:mi mathvariant="normal">O</d:mi><d:mn>4</d:mn></d:msub></d:math>, the magnetoelectric energy can easily overcome the weak magnetocrystalline anisotropy; thus, the Néel vector can be manipulated on demand, either rotated smoothly or reversed suddenly, by combined electric and magnetic fields. We achieve the nonvolatile switching within a few tens of nanoseconds between time-reversed AFM states in macroscopic volumes by voltage pulses. These observations render quasicubic antiferromagnets, like <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"><g:msub><g:mtext>Co</g:mtext><g:mn>3</g:mn></g:msub><g:msub><g:mi mathvariant="normal">O</g:mi><g:mn>4</g:mn></g:msub></g:math>, an ideal platform for the ultrafast (picosecond to nanosecond) manipulation of microscopic AFM domains and may pave the way for the realization of AFM spintronic devices.