Hybrid FFT algorithm for fast demagnetization field calculations on non-equidistant magnetic layers

Abstract

In micromagnetic simulations, the demagnetization field is by far the computationally most expensive field component and often a limiting factor in large multilayer systems. We present an exact method to calculate the demagnetization field of magnetic layers with arbitrary thicknesses. In this approach we combine the widely used fast-Fourier-transform based circular convolution method with an explicit convolution using a generalized form of the Newell formulas. We implement the method both for central processors and graphics processors and find that significant speedups for irregular multilayer geometries can be achieved. Using this method we optimize the geometry of a magnetic random-access memory cell by varying a single specific layer thickness and simulate a hysteresis curve to determine the resulting switching field.

References in corpus (5)

• The design and verification of Mumax3
• Fidimag -- a finite difference atomistic and micromagnetic simulation package
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• Non-uniform FFT for the finite element computation of the micromagnetic scalar potential
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Cited by in corpus (5)

• Coexistence of distinct skyrmion phases observed in hybrid ferromagnetic/ferrimagnetic multilayers
• Dipolar-stabilized first and second-order antiskyrmions in ferrimagnetic multilayers
• Full analytical solution for the magnetic field of uniformly magnetized cylinder tiles
• Accurate finite-difference micromagnetics of magnets including RKKY interaction -- analytical solution and comparison to standard micromagnetic codes
• Proposal for a micromagnetic standard problem: domain wall pinning at phase boundaries