Professor M does Science | Quasi-classical states: does the quantum harmonic oscillator ACTUALLY oscillate?? @ProfessorMdoesScience | Uploaded June 2021 | Updated October 2024, 3 hours ago.
📝 Problems+solutions:
- Quantum harmonic oscillator I: professorm.learnworlds.com/course/quantum-harmonic-oscillator-i
- Quantum harmonic oscillator II: professorm.learnworlds.com/course/quantum-harmonic-oscillator-ii

💻 Book a 1:1 session: docs.google.com/forms/d/e/1FAIpQLScUL187erItvC7GPnNU2pelsueyVFr94nRq2A5Eq2aVRdGiIQ/viewform?pli=1

📚 When we think of a harmonic oscillator what typically comes to mind is the back-and-forth motion of, for example, a mass attached to a spring. For the quantum harmonic oscillator, we mostly discuss the properties of energy eigenstates, but these energy eigenstates do not oscillate! In this video, we ask the question of whether there are any states of the quantum harmonic oscillator that do oscillate. The answer is yes: the coherent states are those that most closely resemble the classical motion, and for this reason they are also called "quasi-classical states".

0:00 Intro
1:06 Classical harmonic oscillator
2:50 Quantum harmonic oscillator
5:40 Classical oscillator vs energy eigenstates
7:39 Coherent states
18:53 Classical oscillator vs coherent states
22:18 Wrap-up

⏮️ BACKGROUND
Quantum harmonic oscillator: youtu.be/OdizRUe84bg
Ladder operators: youtu.be/Kb9twGd25P0
Quantum harmonic oscillator eigenvalues: youtu.be/GkUXscdLQQ0
Ehrenfest's theorem: youtu.be/55RQCCtdlko
Coherent states: youtu.be/x0wk98uMyys

⏭️ WHAT NEXT?
Displacement operator: youtu.be/ypRTLIo-IIc
Coherent state wave function || Maths: youtu.be/0p9pH85SLIU
Coherent state wave function || Concepts: youtu.be/-MaF_TzD4Q8

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Director and writer: BM
Producer and designer: MC