大学物理 ›› 2022, Vol. 41 ›› Issue (5): 6-.doi: 10.16854/j.cnki.1000-0712.210300

• 教学研究 • 上一篇    下一篇

从时间演化角度讲解光电效应

何峰   

  1. 上海交通大学致远学院,物理与天文学院,上海201800
  • 收稿日期:2021-06-22 修回日期:2021-10-11 出版日期:2022-05-20 发布日期:2022-05-10
  • 作者简介:何峰(1977—),男,江苏泰兴人,上海交通大学特聘教授,博士,国家杰出青年基金获得者,主要从事超快激光物理的理论和数值模拟研究工作.
  • 基金资助:

    国家自然科学基金杰出青年基金项目(11925405)资助

Teaching the photoelectric effect in a time-resolved perspective

HE Feng   

  1. Zhiyuan College, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 201800
  • Received:2021-06-22 Revised:2021-10-11 Online:2022-05-20 Published:2022-05-10

摘要: 光电效应是光和物质相互作用的最基本过程之一.一般地,光电效应的讲解是基于爱因斯坦的光电效应公式,是从能量的角度讲解光 电子发射.本文提出一种从时间演化角度讲解光电效应的方法,揭示光电子在任意时刻吸收任意能量的光子,但不同时刻的量子跃迁 振幅相互干涉,时间演化完成后不符合爱因斯坦光电效应公式的事件恰好干涉相消,而符合光电效应公式的事件干涉加强.文章还将 这一理解与费曼路径积分理论相结合,并指出其关联性.有了从时间演化角度对光电效应的理解,可以引导学生设计时域杨氏双缝干 涉实验.

关键词: 光电效应, 时间演化, 杨氏双缝干涉

Abstract: The photoelectric effect is fundamental in laser-matter interaction. Generally, students are taught by introducing the Einstein’s photoelectric-effect equation. In this paper, we propose to teach the photoelectric effect in a time-resolved perspective. According to the time-dependent perturbation theory, the electron may absorb random photons at any time, and the transitions at different moments interfere each other, resulting in the ultimate photoelectron within the expectation of Einstein’s photoelectric-effect equation. The similarity about the time-resolved photoelectric effect and Feynman path integral is analyzed. Students are suggested to conceive a strategy to observed the double-time-slit interference by using two laser pulses. 

Key words: photoelectric effect, time resolved, Young’s double-slit interference