### Abstract

This paper describes a large-scale micromagnetic simulation by using the fast multipole method (FMM) specialized for uniform brick elements. The fast Fourier transform (FFT) is widely used to reduce computational costs of the demagnetizing field calculation. However, the FFT still requires operation counts of O (N log N), where N is the number of elements, which results in the huge computational costs in large-scale problems. To overcome the difficulties, we develop an O (N) approach based on the FMM. In a micromagnetic simulation, an analyzed region is usually subdivided into uniform elements. By making the best use of the periodic structure of uniformly distributed elements, the computational costs of the FMM can be reduced drastically. A large-scale micromagnetic simulation of a single-pole-type head demonstrates the effectiveness of the specialized FMM from the viewpoints of calculation time and memory requirements, compared with the FFT.

Original language | English |
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Article number | 07D514 |

Journal | Journal of Applied Physics |

Volume | 105 |

Issue number | 7 |

DOIs | |

Publication status | Published - 2009 |

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### ASJC Scopus subject areas

- Physics and Astronomy(all)

### Cite this

*Journal of Applied Physics*,

*105*(7), [07D514]. https://doi.org/10.1063/1.3068012

**Micromagnetic simulation by using the fast multipole method specialized for uniform brick elements.** / Takahashi, Y.; Wakao, Shinji; Iwashita, T.; Kanazawa, M.

Research output: Contribution to journal › Article

*Journal of Applied Physics*, vol. 105, no. 7, 07D514. https://doi.org/10.1063/1.3068012

}

TY - JOUR

T1 - Micromagnetic simulation by using the fast multipole method specialized for uniform brick elements

AU - Takahashi, Y.

AU - Wakao, Shinji

AU - Iwashita, T.

AU - Kanazawa, M.

PY - 2009

Y1 - 2009

N2 - This paper describes a large-scale micromagnetic simulation by using the fast multipole method (FMM) specialized for uniform brick elements. The fast Fourier transform (FFT) is widely used to reduce computational costs of the demagnetizing field calculation. However, the FFT still requires operation counts of O (N log N), where N is the number of elements, which results in the huge computational costs in large-scale problems. To overcome the difficulties, we develop an O (N) approach based on the FMM. In a micromagnetic simulation, an analyzed region is usually subdivided into uniform elements. By making the best use of the periodic structure of uniformly distributed elements, the computational costs of the FMM can be reduced drastically. A large-scale micromagnetic simulation of a single-pole-type head demonstrates the effectiveness of the specialized FMM from the viewpoints of calculation time and memory requirements, compared with the FFT.

AB - This paper describes a large-scale micromagnetic simulation by using the fast multipole method (FMM) specialized for uniform brick elements. The fast Fourier transform (FFT) is widely used to reduce computational costs of the demagnetizing field calculation. However, the FFT still requires operation counts of O (N log N), where N is the number of elements, which results in the huge computational costs in large-scale problems. To overcome the difficulties, we develop an O (N) approach based on the FMM. In a micromagnetic simulation, an analyzed region is usually subdivided into uniform elements. By making the best use of the periodic structure of uniformly distributed elements, the computational costs of the FMM can be reduced drastically. A large-scale micromagnetic simulation of a single-pole-type head demonstrates the effectiveness of the specialized FMM from the viewpoints of calculation time and memory requirements, compared with the FFT.

UR - http://www.scopus.com/inward/record.url?scp=65249183286&partnerID=8YFLogxK

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U2 - 10.1063/1.3068012

DO - 10.1063/1.3068012

M3 - Article

VL - 105

JO - Journal of Applied Physics

JF - Journal of Applied Physics

SN - 0021-8979

IS - 7

M1 - 07D514

ER -