Sub-nanosecond signal propagation in anisotropy-engineered nanomagnetic logic chains

Abstract

Energy efficient nanomagnetic logic (NML) computing architectures propagate binary information by relying on dipolar field coupling to reorient closely spaced nanoscale magnets. Signal propagation in nanomagnet chains has been previously characterized by static magnetic imaging experiments; however, the mechanisms that determine the final state and their reproducibility over millions of cycles in high-speed operation have yet to be experimentally investigated. Here we present a study of NML operation in a high-speed regime. We perform direct imaging of digital signal propagation in permalloy nanomagnet chains with varying degrees of shape-engineered biaxial anisotropy using full-field magnetic X-ray transmission microscopy and time-resolved photoemission electron microscopy after applying nanosecond magnetic field pulses. An intrinsic switching time of 100 ps per magnet is observed. These experiments, and accompanying macrospin and micromagnetic simulations, reveal the underlying physics of NML architectures repetitively operated on nanosecond timescales and identify relevant engineering parameters to optimize performance and reliability.

Broadband stripline ferromagnetic resonance spectroscopy of ferromagnetic films, multilayers and nanostructures

“…An important aspect of the current research is the microwave magnetisation dynamics in thin films, multi-layers, and planar nanostructures made from ferromagnetic metallic materials. The interest in these structures is motivated by their potential as a future platform for microwave signal processing [11,12,13,14,15,16], magnetic logics [17,18,19,20,21], magnetic memory [22,23,24,25,26], sensors [27,28,29,30,31], and other areas of science and technology [1].…”

Speed and stability of magnetic chiral motion in a chain of asymmetric thin nanodots

“…16,19) Alternatively, shape control of an individual nanodot could also be a viable approach to enhance speed, stability, and energy-saving. 17,18,20,21) In this case, the nanodot shape needs to be fabricated uniformly, which is still a challenging issue. This could be less sensitive using high-speed regime with a strong driving field, especially in the presence of extrinsic spin wave damping such as Cherenkov radiation 22,23) or in the presence of spin wave emission in the wake of soliton propagation.…”

Recent Advances and Future Opportunities with Magnetic Soft X-ray Microscopy

“…In this talk I will review recent achievements and future opportunities with magnetic x-ray spectromicroscopies. Examples will include the static properties and dynamic behavior of magnetic vortex and skyrmion structures [4,5,6] with potential application to novel magnetic logic elements [7,8]. We have found an asymmetry in the nucleation of magnetic vortex structures [4], that could be attributed to a DMI-like mechanism at the surface by micromagnetic simulations.…”