General Information

Provides an introduction to concepts and techniques of quantum mechanics, at the level of An Introduction to Quantum Mechanics by Griffiths.

Prerequisites

PHYS 3316, PHYS 3317, or PHYS 3327, or appropriate mathematics course(s), coregistration in PHYS 3318, or permission of instructor. Assumes prior experience in linear algebra, differential equations, and Fourier transforms.

Topics Covered

  • Formalism (Hilbert Spaces, Inner Products, Hermitian/Unitary/Projection Operators, Measurement, Postulates of QM, Discrete Eigenstates and Eigenvalues, Time Evolution, Basis Representations, Compatible Observables, Operators with Continuous Spectra, Uncertainty Principle, Conjugate Variables)
  • Schrodinger Equation in 3D (Spherically-symmetric Potentials, Spherical Harmonics, the Radial Equation, the Hydrogen Atom, 3D harmonic oscillator, Angular Momentum Algebra, Spin Algebra, Addition of Angular Momentum, Clebsch-Gordon madness)
  • Multiple Particles (Fermions/Bosons, Symmetric/Anti-Symmetric Wave Functions, Bloch’s Theorem, Baby Band Structure, Spin Statistics, the Helium Atom, the Periodic Table, the H2 molecule)
  • Symmetries and Conservation Laws (conserved quantities, parity, translation, rotation, selection rules, degeneracy)
  • Time-independent perturbation Theory (first & second order non-degenerate perturbation theory, first order degenerate perturbation theory, Hydrogenic fine structure)
  • Variational Principle (Helium Atom, H2 molecule ion)
  • WKB (the WKB approximation, tunneling, connection formulas)
  • Scattering (partial wave analysis, Born approximation)
  • Time-Dependent Perturbation Theory (2-level systems, transition probabilities, the Adiabatic Approximation, Absorption/Emission)

Workload

  • Weekly problem sets (14 total), optional discussion sections, 1 mid-term exam (roughly 90 minutes), 1 final exam (2 hr 30 min) [SP23]
  • There are psets every week (even the week of the midterm), each taking about 10 hours. This course is honestly a good bit of work. It is definitely time consuming, but the material is accessible and well taught. The psets are fair compared to the lecture material. Depending on the professor, there might be a more experimental/materials focus compared to a more theoretical focus. For example, this semester we didn’t learn infinite dimensional Hilbert spaces, but when Eanna Flanagan teaches it I believe he covers that. [SP25]

General Advice

  • The standard operating procedure for physics courses at Cornell applies fairly well to this class. Lecture and recitation attendance is a good idea unless you know you can get by without it; Griffiths is the bible of this course, and is the source you should go to for practice problems, alternative explanations, and self-study; work problem sets alone first, and then in groups, etc. Griffiths really is your friend. [SP23]
  • Griffiths is really useful for the first half of the course. We didn’t really use it for the second half. This class is comparable to grad quantum in a lot of ways, so good prep for all kinds of physics reserach. [SP25]
  • Attend office hours, read through Griffiths and Sakurai. [SP25]

Testimonials

  • This class basically follows Griffiths, taking as a given that you know how to solve the Schrodinger Equation in 1D for the canonical examples like the infinite square well and harmonic oscillator with your eyes closed (Chapters 1-2) and assuming some familiarity with formalism (Chapter 3). In Spring 2023, the class started fairly slow, taking four weeks or so to cover formalism, and then three more weeks to cover Chapter 4 content. After that, the pace increased significantly, moving through the remainder of Griffiths at about a chapter per week. This is okay - the later chapters are less conceptually rich, not to mention shorter. The problem sets were challenging - typically three Griffiths level problems (of the two-star variety, if you are familiar with the lingo) and then one problem that is longer and deeper that the course staff cooks up. The exams were fair, but long. You will need Calc III, Linear Algebra, and Differential Equations at the 1920/2930/2940 level for this class. For those who are expecting to continue on to graduate study of physics, I highly recommend this class, because this level of quantum mechanics is typical fodder for the Q exam at many universities. [SP23]
  • I really enjoyed this class minus the fact that it was my highest workload (compared to phys 4444 and phys 6554) and at 9am. The lectures are well taught and the material moves at an accessible pace. The homework is a lot, but doable in my opinion. [SP25]
  • I feel like this is the course where I am actually understanding quantum for the first time. It essentially covers the topics of PHYS 3316 and 3317 but with more rigorous math. It is challenging, but if you attend office hours, it will be alright. [SP25]

Resources

Past Offerings

Semester Professor Median Grade Syllabus
Spring 2023 Katja Nowack A- PHYS4443_SP23.pdf
Spring 2024 Katja Nowack    
Spring 2025 Katja Nowack