Inverse-design magnonic devices

Abstract

The field of magnonics offers a new type of low-power information processing, in which magnons, the quanta of spin waves, carry and process data instead of electrons. Many magnonic devices were demonstrated recently, but the development of each of them requires specialized investigations and, usually, one device design is suitable for one function only. Here, we introduce the method of inverse-design magnonics, in which any functionality can be specified first, and a feedback-based computational algorithm is used to obtain the device design. We validate this method using the means of micromagnetic simulations. Our proof-of-concept prototype is based on a rectangular ferromagnetic area that can be patterned using square-shaped voids. To demonstrate the universality of this approach, we explore linear, nonlinear and nonreciprocal magnonic functionalities and use the same algorithm to create a magnonic (de-)multiplexer, a nonlinear switch and a circulator. Thus, inverse-design magnonics can be used to develop highly efficient rf applications as well as Boolean and neuromorphic computing building blocks.

Advances in Magnetics Roadmap on Spin-Wave Computing

“…However, while testing a single parameter set by performing micromagnetic simulations is a fast alternative to experiments, the optimization of complex high dimensional design parameters such as the device shape is a complicated task that requires the application of smart optimization routines in order to ensure feasibility. In the case of relatively small numbers of binary design variables, it has been shown that a simple binary search algorithm in conjunction with a fast forward solver can lead to very good optimization results for magnonic multiplexers [119]. However, with increasing dimensionality of the design space, more sophisticated methods such as gradient based algorithms have to be used.…”

“…VI.A) [313]. Another circulator was proposed based on the dipolar interaction with the resonator taking advantage of circulating modes [314] and based on the inversedesign method (Section VII-C) [119]. The first experimental realization of the spin-wave diode was made for the doublelayer system in which the dispersion modelling was used to slow down a spin wave in one direction of propagation [180].…”

“…In this approach, any functionality can be specified first, and a feedback-based computational algorithm is used to obtain the device design. Recently, inversedesign was also utilized and validated numerically in the field of magnonics [119], [378].…”

Controlling the three dimensional propagation of spin waves in continuous ferromagnetic films with an increasing out of plane undulation

“…However, exploring the third dimension is crucial indeed, because a 3D distribution of the magnetization offers a new degree of freedom, which in general allows, from one side, to fit more functionality into a smaller space, and hence to considerably increase the density of elements in magnonic devices 18 , 19 , and from the other, further possibilities for the SW dynamics and transport (e.g., vertical magnon transport, nonreciprocal coupling 20 – 22 ). More recently, the opportunity of designing 3D ferromagnetic systems where ferromagnetic layers are linked by a large number of vertical connections has been proposed in the perspective of the so-called neuromorphic networks 23 – 25 .…”

FORC-Diagram Analysis for a Step-like Magnetization Reversal in Nanopatterned Stripe Array

“…One of the promising candidates for replacing conventional semiconductor electronics are spin-wave-based devices [ 1 , 2 , 3 ]. The field of science that studies signal generation and transport with spin waves is called magnonics.…”