Bidirectional magnetization switching of a ferrimagnetic insulator with monochiral molecules

Abstract

Recent studies have demonstrated that magnetization switching in ferromagnets can be achieved through adsorbing chiral molecules on the surface without the need for current or external magnetic fields, offering a low-power mechanism for applications in spintronic devices. Opposite chirality molecules cause opposite direction reversals of magnetization through the chiral-induced spin selectivity (CISS) mechanism. In this study, we demonstrate bidirectional magnetization switching in thin films of ferrimagnetic insulator TmIG using a single chirality molecule - a Cu metallopolymer of d-leucine. Through UV-VIS circular dichroism and X-ray absorption spectroscopy, we determined that switching between different magnetic orientations is associated with interactions of the d-leucine with the two distinct sublattices of the Fe ions in the TmIG, at octahedral and tetrahedral sites. Our study demonstrates the unexpected versatility of the CISS mechanism for magnetization switching in ferrimagnets using single chirality materials, thereby expanding the potential applications of chiral molecule adsorption-induced magnetization flipping.