Ferroelectricity-controlled magnetic ordering and spin photocurrent in NiCl₂/GeS multiferroic heterostructures

Abstract

Controlling magnetism solely through electrical means is indeed a significant challenge, yet holds great potential for advancing information technology. Herein, our investigation presents a promising avenue for electrically manipulating magnetic ordering within 2D van der Waals NiCl2/GeS heterostructures. These heterostructures, characterized by their unique magnetic-ferroelectric layer stacking, demonstrate spin-constrained photoelectric memory, enabling low-power electrical writing and non-destructive optical reading. The two orientations of the polarization in the GeS ferroelectric layer bring about changes in the ground state configuration, transitioning from ferromagnetic (FM) to antiferromagnetic (AFM) orderings within the NiCl2 magnetic layer. Correspondingly, the light-induced charge transfer prompts either spin-polarized or unpolarized currents from the FM or AFM states, serving as distinct "1" or "0" states, and facilitating applications in logic processing and memory devices. This transition stems from the interplay of interfacial charge transfer mechanisms and the influence of the effective electric field (Eeff), bringing a non-volatile electric enhancement in the magnetic anisotropy energy (MAE) within the NiCl2/GeS heterostructure. Overall, our study highlights the NiCl2/GeS heterostructure as an optimal candidate for realizing spin-dependent photoelectric memory, offering unprecedented opportunities for seamlessly integrating memory processing capabilities into a single device through the utilization of layered multiferroic heterostructures.