正则动量面面观  

MANY FACES OF CANONICAL MOMENTUM

作　　者：徐湛[1] 

机构地区：[1]清华大学物理系,北京100084

出　　处：《物理与工程》2017年第5期3-9,共7页Physics and Engineering

摘　　要：对于带电粒子在磁场中的运动,一个很重要的概念是粒子的正则动量不同于它的机械动量,而这一点经常被忽视或者被混淆。本文从正则动量的基本定义出发,从经典的和量子的两方面分析了正则动量和机械动量的关系,指出正则动量才是基本的动力学变量。最后以磁镜装置为例说明了如何应用正则动量简明地给出问题的答案。For movement of a charged particle in a magnetic field, a very important concept is that the canonical momentum of the particle is different from its mechanical momentum, whichis often overlooked or confused. Based on the fundamental definition of canonical momentum, this paper analyzes the relationship between canonical momentum and mechanical momentumfrom classical and quantum aspects, and emphasizes that the basic dynamic variable is the canonical momentum. Finally, as an example, the magnetic mirror device is studied to illustratehow the canonical momentum concisely gives the answer to a problem.

关 键 词：磁场 矢量势 正则动量 规范变换 磁镜装置 

分 类 号：O413.1[理学—理论物理]