Electronically Driven Magnetoelectric Coupling in Co/La:Hf_0.5Zr_0.5O₂ Heterostructures for Energy-Efficient...

Magnetoelectric materials enable low-power memory devices by leveraging the electric control of magnetization. The discovery of ferroelectricity in doped hafnia has unlocked further opportunities since the distinct ferroelectric switching mechanism in this material can enable robust and multilevel modulation of magnetization by electric field, if combined with appropriate magnetic materials. Here, we demonstrate a 5% electric field-induced modulation of the saturation magnetization in a cobalt layer, driven by ferroelectric switching of an adjacent epitaxial La(1%):Hf_0.5Zr_0.5O₂ film. Dichroic imaging with synchrotron radiation confirms that ferroelectric switching induces a magnetic change. We show that the response time is faster than 500 ns (limited by the setup time resolution threshold) and that energy consumption is 6 nJ. This low energy consumption is mainly enabled by the absence of relevant leakage current contribution (10 nA/cm² at 500 mV). The found response time and energy-efficient behavior point to the presence of an electronically driven modulation of magnetism (i.e., conventional magnetoelectric effects), which is confirmed by theoretical calculations and compositional analysis. Additionally, a multilevel magnetoelectric response is observed, enabling neuromorphic-like behavior. The demonstration of magnetoelectric coupling in a system based on CMOS-compatible materials offers a viable route toward the development of low-power beyond von-Neumann technologies.