PHY 341

Welcome to PHY 341 – Quantum Mechanics I homepage

We will use this space to post extra course materials, like homework, solutions, announcements, etc.

If you have any interesting and related links, we can add them too.

• Announcements and homework
  • Asynchronous video: Apr 10 Mon: Schwarz inequality (15:40) || Jan 19 Fri: JupyterHub and Jupyter notebook (17:46)
  • Class recording: Apr 22 Mon: Energy-time relation || Apr 19 Fri: Dirac notation || Apr 17 Wed: Uncertainty principle revisited || Apr 12 Fri: Coordinate and momentum spaces || Apr 10 Wed: Eigenstates of momentum || Apr 5 Fri: Eigenstates of Hermitian operators || Apr 3 Wed: Eigenfunctions || Apr 1 Mon: Hilbert space || Mar 27 Wed: Visualizing bound states || Mar 25 Mon: Bound states in SWPs || Mar 22 Fri: Scattering from square well potentials || Mar 20 Wed: Scattering states in delta potential || Mar 18 Mon: Bound state in delta potential || Mar 8 Fri: Dirac delta func || Mar 6 Wed: Position and momentum wf || Mar 4 Mon: Free particles || Mar 1 Fri: Expect. values with operators || Feb 28 Wed: SHO with computation || Feb 26 Mon: Hermitian conjugates || Feb 21 Wed: SHO energy ladder || Feb 20 Tue: Raising & Lowering ops || Feb 16 Fri: Basis expansion || Feb 14 Wed: Orthogonality and projection || Feb 12 Mon: Discrete states || Feb 7 Wed: Stationary states, superposition || Feb 5 Mon: Time-Indep. Sch Eqn || Feb 2 Fri: Commutators || Jan 31 Wed: Momentum, operators || Jan 26 Fri: Averages, simulation of free fall || Jan 24 Wed: Probability, Measurement || Jan 22 Mon: Schrodinger equation
  • Tutor schedule: Tue 2-3; Wed 4:15-5:15 (SENG 217D plus zoom)
  • Announcement Jan 19 2024: Research Experience for Undergraduates
  • PHY 341 Syllabus
  • Useful math formulas
  • Concepts: Operators || Uncertainty principle || Possible wave functions || ChatGPT solutions of linear eqns || Bound and scattering states || Inf. potential well || QM Concept 1 || Wave function 1

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  • Homework 1a (due Feb 2 Fri)
  • Homework 1b (due Feb 9 Fri)
  • Homework 2a (due Feb 16 Fri)
  • Homework 2b (due Feb 23 Fri)
  • Homework 2c (due March 8 Fri)
  • Homework 2d (due March 25 Mon)
  • Homework 2e (due Apr 1 Mon)
  • Homework 3a (due Apr 19 Fri)
  • Homework 3b (due Apr 26 Fri)
• Codes and other links
  The programs are in the Jupyter notebook format. You can download it and open it with Jupyter. If you do not have access to a Jupyter installation or server, you can go to try.jupyter.org on the cloud, and upload the notebook there.
  Note: Due to some weird, nonsensical rule of the site disallowing the “.ipynb” file extension, I have the programs in .zip (or plain .txt) formats. If you download a zip file, unzip it to recover the .ipynb file. If you download the .txt file (right click then save), just rename “somefile-ipynb.txt” to “somefile.ipynb”.
  • Local Jupyter/Python server. For the first time, make sure to login using UMD credentials via ssh ( eg putty on Windows) with putty rps.cscvr.umassd.edu. Simply exit after login. This will create a proper directory structure. Subsequently, you can login by clicking on the link.
  • cocalc.com (if you have nothing better)
  • Motion of a quantum oscillator: You may run or edit this program in your web browser from (a) homepage here (scroll to bottom); or (b) Glowscript version; or (c) Program_8.2_sdlf.ipynb. Download and save the named program, making sure to extract all including the associated library files, ode.py, vpmnb.py in one place. Upload the files to your Jupyter notebook.
  • Simulation of averages by ramdom sampling in free fall in zip format.
  • Superposition of states in zip format. HW 2a refers to this program.
  • Exploration of discreteness of states in zip format.
  • Expansion/integrals with Sympy in zip format.
  • SHO with sympy in zip format.
  • SHO classically forbidden zones in zip format.
  • SHO allowed energies in zip format.
  • Momentum wf of a square in zip format.
  • Momentum wf of a Gaussian in zip format.
  • Square well: unbound states in zip format.
  • Square well: allowed energies and wave functions in zip format.
  • Square well: visualizing bound states in zip format.