Long-distance propagation of short-wavelength spin waves

TLDR

Spin waves are being explored as a highly energy‑efficient alternative to CMOS for future computing architectures, but their practical use is limited by the difficulty of exciting short‑wavelength waves needed for device scaling. The study introduces a new method for generating nanometer‑scale spin waves. The approach employs ferromagnetic nanowires fabricated on a 20‑nm Y₃Fe₅O₁₂ film strip. Measured results show 50‑nm wavelength spin waves propagating over 60 µm with a group velocity of 2,600 m s⁻¹, exceeding the speeds of domain‑wall and skyrmion motion.

Abstract

Abstract Recent years have witnessed a rapidly growing interest in exploring the use of spin waves for information transmission and computation toward establishing a spin-wave-based technology that is not only significantly more energy efficient than the CMOS technology, but may also cause a major departure from the von-Neumann architecture by enabling memory-in-logic and logic-in-memory architectures. A major bottleneck of advancing this technology is the excitation of spin waves with short wavelengths, which is a must because the wavelength dictates device scalability. Here, we report the discovery of an approach for the excitation of nm-wavelength spin waves. The demonstration uses ferromagnetic nanowires grown on a 20-nm-thick Y 3 Fe 5 O 12 film strip. The propagation of spin waves with a wavelength down to 50 nm over a distance of 60,000 nm is measured. The measurements yield a spin-wave group velocity as high as 2600 m s −1 , which is faster than both domain wall and skyrmion motions.