Deterministic Control of Magnetization Dynamics in Reconfigurable Nanomagnetic Networks for Logic Applications

Abstract

Information processing based on nanomagnetic networks is an emerging area of spintronics, as the energy consumption and integration density of the current semiconductor technology are reaching their fundamental limits. Nanomagnet-based devices rely on manipulating the magnetic ground states for device operations. While the static behavior of nanomagnets has been explored, little information is available on their dynamic behavior. Here, we demonstrate an additional functionality based on their collective dynamic response and explore the concept utilizing networks of bistable rhomboid nanomagnets. The control of the magnetic ground states of the networks was achieved by the geometrical design of the nanomagnets instead of the conventional interelement dipolar coupling. Dynamic responses of both the ferromagnetic and antiferromagnetic ground states were monitored using broadband ferromagnetic resonance spectroscopy, the Brillouin light scattering technique, and direct magnetic force microscopy. Micromagnetic simulations and numerical calculations validate our experimental observations. This method would have potential implications for low-power magnonic devices based on reconfigurable microwave properties.

Microwave assisted gating of spin wave propagation

“…1(a) due to the shape induced anisotropy. 19 However, due to the 80-nm-thick CPW, we could not measure spin wave intensities using the BLS laser probe for the nanomagnets under the CPW.…”

“…18 Rhomboid shaped nanomagnets are quite different with respect to a rectangular nanomagnet in terms of their remanent magnetic states when an initialization field is applied along the short axis of the nanomagnet. 19 Such shape engineered structures are found to be interesting for tunable microwave operation and spin wave (SW) propagation without a bias magnetic field. Gating of spin waves was earlier achieved by switching a nanomagnet in the nanowire by applying an external magnetic field on a strategically fabricated nanowire with a "defect."…”

Temperature Dependence of Spin Pinning and Spin-Wave Dispersion in Nanoscopic Ferromagnetic Waveguides

“…The recent progress in the fabrication technology leads to the development of nanoscopic magnetic devices in which the width and the thickness ℎ become comparable [21][22][23][24][25][26][27][28][29]. The description of such waveguides is beyond the thin strip model of effective pinning, because the scale of nonuniformity of the dynamic dipolar fields, which is described as "effective dipolar boundary conditions", becomes comparable to the waveguide width.…”

Coupled magnetic nanostructures: Engineering lattice configurations

“…37 The input parameters for the simulations include, saturation magnetization (Ms) = 800 emu/cm 3 , exchange constant = 1.3 µerg/cm, damping constant = 0.008 with zero uniaxial anisotropy. Cubic cells, each of volume (5 nm) 3 were used to discretize the entire mask for simulation, adopted from the corresponding SEM images with the provision for applying 2D periodic boundary conditions. The saturated states for all the structures were first obtained by applying 2kOe of field along the x-axis and brought back to zero thereafter to initialize the remanent configurations.…”