大学物理 ›› 2026, Vol. 45 ›› Issue (1): 23-.doi: 10.16854/j.cnki.1000-0712.250096

• 教学讨论 • 上一篇    下一篇

稳恒外磁场下磁偶极子的势函数

李志兵   

  1. 中山大学·深圳 理学院,广东深圳 518107
  • 收稿日期:2025-02-26 修回日期:2025-04-23 出版日期:2026-04-13 发布日期:2026-04-19
  • 作者简介:李志兵(1962—),男,广东东莞人,中山大学理学院教授,博士,主要从事大学物理教学、纳米电子学和统计物理研究.
  • 基金资助:
    国家自然科学基金(11474131)资助

The potential of magnetic moment in a static external magnetic field

LI Zhibing   

  1. School of Science, Shenzhen Campus, Sun Yatsen University, Shenzhen 518107, China
  • Received:2025-02-26 Revised:2025-04-23 Online:2026-04-13 Published:2026-04-19

摘要: 电动力学通过让磁场下磁偶极子受到的作用力等于势函数的负梯度,定义稳恒磁场下磁偶极子的势函数.从这个定义并不能知道该势函数的物理意义.本文从场的角度分析势函数的意义,指出磁场下宏观磁偶极子的势函数和原子磁偶极矩的相应能量虽然具有相同的表达式,但是物理意义却不同,后者实际上是原子内能的一部分.

关键词: 磁偶极子, 能量, 势能

Abstract: A static external magnetic field exerts a force on magnetic moment which is equal to negative gradient of the potential, that is the definition of the potential in electrodynamics. However, the physical meaning of the potential is not given by this definition. We will discuss the physical content of the potential, showing that the potential of a macroscopic magnetic moment and magnetic field-depending energy of an atom are different in physics, although they have the same expression. The one for the atom is part of the internal energy of the atom.

Key words:  magnetic moment, energy, potential