Change of the magnetic structure and the generation of the magnetic friction under the lattice motion

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K13857
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 13010:Mathematical physics and fundamental theory of condensed matter physics-related
• Research Institution: Shiga University (2023); Kyushu University (2022); National Institute for Materials Science (2021)
• Principal Investigator: Komatsu Hisato 滋賀大学, データサイエンス学系, 助教 (50812963)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 磁気摩擦 / 平均場理論 / 有限サイズ効果

Outline of Final Research Achievements

In this study, the relationship between the magnetic structure and the motion of the object in a finite-size system and its effect on the value of the frictional force were investigated, using a largely simplified model of magnetic friction. As a result of numerical simulations and theoretical considerations, it was confirmed that when the resistance coefficient γ of the object motion was small, the stick and slip states were separated as if they had been two separate metastable states. When γ was large, on the other hand, such separation did not occur and the lattice motion can be treated as a kind of thermal activation process.
In parallel with this study, the finite-size effect of the statistical mechanical model itself was also considered. Specifically, for the finite-sized Ising model with long-range interactions, deviation from the mean-field approximation was calculated using the perturbation theory.

Free Research Field

統計物理学

Academic Significance and Societal Importance of the Research Achievements

stick状態とslip状態が準安定状態のように分離する例の存在や、有限サイズ系を考察することの重要性などの、この研究を通じて得られた知見は今後磁気摩擦に限らず摩擦という現象全般の微視的なメカニズムに関する研究を進める上で興味深いものとなる。
また、有限サイズ効果そのものを理論的に考察する手法の構築は、将来摩擦に限らず様々な現象の考察に役立つことが期待される。