课程高等物理学.pptVIP

20 世纪初物理天空上有几朵乌云 第八讲 量子力学绪论 量子力学的诞生过程 “概率幅”的引入 量子力学的诞生过程 It was beginning from the issue about light …… Newton theory: Light is made up of tiny balls. Maxwell theory: Light is a kind of wave . But there were some problems that can not be explained by both of theories above. Blackbody Radiation Photoelectric Effect Compton scattering Spectrum of Hydrogen atom Planck’s explanation of the blackbody radiation In 1900, Planck explained the blackbody radiation by supposing that light is made up of many photons. 量子力学的诞生过程 In 1905 Einstein’s Explanation of Photoelectric Effect Einstein’s Explanation of Photoelectric Effect In 1923 Compton scattering COMPTON SCATTERING (cont) 人们终于承认光还有“粒子性”，当然早就承认光也有“波性” How about electrons--the tiny particles of matter ? Newton theory thought it should be a particle. But there were also a few problems that can not be explained by classical physics…… Spectrum of Hydrogen atom The scattering of electrons on a surface of crystal 1924年 de Broglie 战战兢兢提出一个大胆的假设：电子也有“波性” The strange (and beautiful) world of Quantum Mechanics Duality De Broglie - Heisenberg Two Slit experiments With waves (water waves) With electrons 概率幅——电子双缝干涉实验 预备知识 不干涉的宏观粒子 干涉的光波 不干涉的光波 电子的双缝实验证明电子具有“波”的干涉性 对电子“波”的干涉现象的描述 寻找解释电子“波”的干涉现象的方法 引入新概念—概率幅 probability amplitude Double-Slit Experiment with a machine gun! Double-Slit Experimentto illustrate wave nature of light Double-Slit Experiment to illustrate wave nature of light Double-Slit Experimentwith non-interference light sources Double-Slit Experimentwith electronics Double-Slit Experimentwith electronics Double-Slit Experiment with electronics Double-slit experiment succeeds in a single hydrogen molecule Lawrence Berkeley National Laboratory (LBNL; Berkeley, CA) D Akoury, K Kreidi, T Jahnke, et al., Science 318, 949 (Nov. 9, 2007). How to explain it ? ! How to explain it ? ! Watching the electrons! Continue to watch the electrons! Don’t use such bright light source! If the electrons are not seen, we have