Nonreciprocal spin wave channeling in ferromagnetic/heavy-metal nanostrips

Nonreciprocity, unidirectionality, and channeling are essential concepts for potential magnonic applications. Nonreciprocity and unidirectionality ensure the efficient propagation of spin waves along predetermined paths with preferential directions, disrupting the symmetry of counterpropagating waves. Channeling fosters the development of intricate spin-wave networks, enabling more sophisticated functionalities. Integrating these concepts into practical applications will shape the future of spin-wave-based information processing devices. This article theoretically studies the dynamics of spin waves in a ferromagnetic strip coupled to a heavy-metal strip, where the nonreciprocity, unidirectionality, and channeling effects are analyzed. Both backward volume (BV) and Damon–Eshbach (DE) configurations are considered, where the lateral dimensions of the heavy-metal and ferromagnetic strips can differ. Calculations show notable nonreciprocal channeling of spin waves in both DE and BV modes. In the BV configuration, the dispersion is reciprocal with nontrivial localization of lateral confined modes. It is shown that the waves can be channeled into the zones in contact with the HM, where the Dzyaloshinskii–Moriya interaction is active. In the DE configuration, the waves exhibit nonreciprocal spin-wave dispersion, allowing unidirectional and channeled spin-wave propagation. The main results are compared to micromagnetic simulations, where an excellent agreement between both methods is obtained. These findings are relevant for envisioning advanced magnonic devices, enabling precise control over spin-wave propagation for innovative, low-power, high-speed information processing. • The work presents a novel nanometric system that can serve to channel the spin waves. • Spin-wave channeling is observed for backward volume and Damon–Eshbach configurations. • Nonreciprocal spin-wave channeling is obtained, which can be useful for designing advanced magnonic devices, like magnonic diodes.