Gating of an Antiferromagnet with Hydrogen

Robust and energy efficient electrical manipulation of antiferromagnets (AFM), be that via currents or voltages, is a highly desirable functionality owing to a number of inherent advantages of AFMs over ferromagnets (FM). Here, we present results of magneto-ionically gating an AFM with hydrogen, in a Co/Co₉₀Ni₁₀O exchange-biased (EB) heterostructure. In this system, EB serves as a means to probe changes occurring in the AFM as well as the interface. Because domain wall creep dynamics is highly sensitive to the local properties of the heterostructure, we investigate the effect of gating on EB through measurement of domain wall velocities (in Co) using a wide field MOKE. This ensures that extracted parameters such as the EB, depend only on the local properties of the gated area. We report a reversible enhancement of the EB field by up to 100% upon gating, suggesting considerable modulation of bulk and or interfacial characteristics of the AFM. These early results show that AFMs are susceptible to ionic gating, and we believe our work can pave the way for more robust electrical control of AFMs, pushing the boundaries of the exciting field of AFM spintronics.