Distinct Transmission of Left- and Right-Handed Magnon Modes in Compensated Ferrimagnet/Antiferromagnet Structures.

Abstract

The chirality of magnons, exhibiting left- and right-handed polarizations analogous to the counterparts of spin-up and spin-down, has emerged as a promising paradigm for information processing. However, the potential of this paradigm is constrained by the controllable excitation and transmission of chiral magnons. Here, the magnon transmission is explored in the Gd₃Fe₅O₁₂/NiO/Pt structures. It is demonstrated that both left- and right-handed magnon modes, thermally generated in the compensated ferrimagnet Gd₃Fe₅O₁₂, can efficiently propagate through the antiferromagnetic NiO layer. Remarkably, these modes undergo distinct decay processes in NiO, manifested by different evolutions of the spin diffusion length with temperature. This behavior can be explained by an exchange model rooted in the spin-flop magnetic configuration between Gd₃Fe₅O₁₂ and NiO, which establishes a chiral selection rule for magnon transmission. These findings offer significant fundamental insight into controlling chiral magnons, opening avenues for chirality-based magnonics.