Switching magnon chirality in artificial ferrimagnet

Abstract

Chirality, an intrinsic degree of freedom, has been barely exploited as the information carriers in data transmission, processing, computing, etc. Recently the magnons in antiferromagnets were proposed to carry both right-handed and left-handed chiralities, shedding a light on chirality-based spintronics in which chirality-based computing architectures and chiral magnonic devices may become feasible. However, the practical platform for chirality-based spintronics remains absent yet. Here we report an artificial ferrimagnetic Py/Gd/Py/Gd/Py/Pt multilayer by which the switching, reading, and modulation of magnon chirality are demonstrated. In particular, the coexisting resonance modes of ferromagnetic and antiferromagnetic characteristics permit the high adjustability and easy control of magnon chirality. As a main result, we unambiguously demonstrated that Py precessions with opposite chiralities pump spin currents of opposite spin polarizations into the Pt layer. Our result manifests the chirality as an independent degree of freedom and illustrates a practical magnonic platform for exploiting chirality, paving the way for chirality-based spintronics.

Temperature-Induced Magnonic Chern Insulator in Collinear Antiferromagnets

“…3 (e), opposite behavior to the above one. As reported in the experimental works [53][54][55][56][57], the magnon chirality in antiferromagnets can be distinguished by the magneto-Raman spectroscopy due to the angular momentum conservation [53], the polarized neutral scattering technique [54] or very recent developed polarization-selective spectroscopy [55][56][57]. These experimental methods greatly coincide with our system.…”

Chirality dependence of spin current in spin pumping

“…One recent experiment designed a cleaver method in which spin pumping from Py into Pt layers by left-handed and right-handed Py magnetic precessions were realized independently 9 . In an artificial ferrimagnet of Py/Gd/Py/Gd/Py/Pt multilayer in which the Py and Gd are antiferromagnetically coupled, the net magnetization always precesses around a magnetic field with right-handed chirality, the same as the magnetization precession in a ferromagnet.…”

Chirality as Generalized Spin-Orbit Interaction in Spintronics

“…It is nowadays well appreciated that the antiferromagnet and ferrimagnet can host magnons of both left-handed and right-handed circular polarizations or "chiralities" [507][508][509] that are carried by the so-called and modes, which provides additional degree of freedom and tunability than that of ferromagnet. In particular, the magnon chirality can be manipulated via the modulation of the ratio of the sublattice magnetization [510,511]. The manipulation of righthanded and left-handed chiralities in antiferromagnets and ferrimagnets enables the design of chirality-based magnonic devices such as field-effect transistor [512] and chirality-based logic devices [513,514].…”