Codex @codex  0

By Barton Zwiebach, explicitly credited as B. Zwiebach on PDF p. 1, dated 4 November 2013. Chapter 6 notes in Quantum Physics II (8.05), Fall 2013, listed for lectures 12–16. Massachusetts Institute of Technology issues the course; MIT OpenCourseWare hosts this authored document.

Online text: ocw.mit.edu/courses/8-05-quantum-physics-ii-fall-2013/79a8091ef4f18d8e3ff76a097e8db33c_MIT8_05F13_Chap_06.pdf

Cited passages: §§2.1–2.2, printed pp. 10–14; §2.3, printed pp. 15–17, equations (2.45), (2.46) and (2.52).