Magnetoelectric effect in multiferroic metals via a direct spin-charge interaction

Abstract

Much is known about the magnetoelectric effect of multiferroic insulators, yet little is understood about multiferroic metals. In this work, we propose a stacking engineering strategy based on monolayer magnets to construct multiferroic metals, with validation through first-principles calculations on six experimentally synthesized materials. Such multiferroic metals exhibit predominantly linear magnetoelectric response, originating from direct spin-charge interactions as a result of external field-modulated Fermi energy. This fundamentally differs from spin-charge-lattice or spin-orbit coupling mechanisms in multiferroic insulators, offering application advantages in the field of high-speed response. We derive a universal formula for understanding the magnetoelectric coupling in these multiferroic metals. Our work provides insights for exploring magnetoelectric coupling mechanisms and designing functional materials with strong magnetoelectric coupling.

Accepted by PRB