摘要
本文试图回答《费曼物理学讲义第3卷》第13-8节中提出的一个"疑难问题",即该讲义导出了在有吸引性缺陷的一维晶格中,存在着一个处于能带上方的束缚态能级,那么其物理意义是什么?我们的分析方法包括:构造新的捕陷态,找出该问题的全部可能的解,以及对散射振幅重新进行解析延拓。各种方法导致的结论是一致的,即确实存在着费曼所说的那个处于能带上方的一个束缚态能级,然而该晶格的缺陷一定是排斥性的,而不能是吸引性的。
This paper tries to answer the ＂puzzle＂ in Section 13-8 of Feynman Lectures on Physics Volume 3,which claimed that in a one-dimensional lattice with an attractive imperfection there is a bound state above the energy band,and asked what its physical meaning is.Our analysis includes constructing a new trapped state,finding all possible solutions to the problem and reanalyzing the analytic continuation of the scattering amplitude.Various methods lead to a consistent conclusion that indeed there is an energy level of bound state above the energy band as Feynman said,but the lattice imperfection should be repulsive instead of attractive.
出处
《物理与工程》
2017年第6期27-30,共4页
Physics and Engineering
关键词
晶格缺陷
捕陷态
束缚能级
散射振幅
解析延拓
lattice imperfection
trapped state, bound state level
scattering amplitude
analytic continuation
