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: Mar 13 Mon: Schwarz inequality (15:40) || Feb 8 Wed: Symbolic computation with Sympy (10:52) || Feb 3 Fri: Visualizing superposition (10:35) || Jan 23 Mon: JupyterHub and Jupyter notebook (17:46)
  • Class recording: Apr 24 Mon (Overview, qubits) || Apr 21 Fri (Infinite spherical well) || Apr 19 Wed (Radial Sch eqn, effective potential) || Apr 14 Fri (Angular wf, spherical harmonics) || Apr 12 Wed (Separation of Sch eqn in spherical coordinates) || Apr 10 Mon (Schrodinger eqn in 3D) || Apr 7 Fri (Basis transformation, time evolution of two states) || Apr 5 Wed (Operator matrix and eigenvectors) || Apr 3 Mon (Matrix formulation in Hilbert space) || Mar 31 Fri (Momentum space wf) || Mar 29 Wed (Dirac notation) || Mar 27 Mon (Uncertainty between observables A,B) || Mar 22 Wed (Momentum space part 1, part 2) || Mar 20 Mon (Eigenstates of Hermitian operators) || Mar 17 Fri (Eigenstates) || Mar 15 Wed (Hilbert Space/Dirac notation) || Mar 13 Mon (Bound states in a square well) || Mar 3 Fri (Unbound states in a square well) || Mar 1 Wed (States in delta potential/review) || Feb 24 Fri (Wave packet, Dirac delta func) || Feb 22 Wed (Free particle, wave packet) || Feb 21 Tue (SHO, analytic & numeric methods) || Feb 15 Wed (forbidden zones, correspondence principle) || Feb 13 Mon (Hermitian operators) || Feb 10 Fri (SHO, operator method) || Feb 8 Wed (expansion coefficients) || Feb 6 Mon (infinite square well) || Feb 3 Fri (visualizing discrete states) || Feb 1 Wed (superposition) || Jan 30 Mon (stationary states) || Jan 27 Fri (operators) || Jan 25 Wed (expectation values) || Jan 23 Mon (prob dist in free fall) || Jan 20 Fri (probability) || Jan 18 Wed (wave func)
  • Announcement Mar 15 2023: Midterm survey (deactivated as of Mar 31)
  • Announcement Jan 17 2023: Scheduled class, 12-1 MWF, SEng-102
  • Announcement Jan 17 2023: Research Experience for Undergraduates
  • PHY 341 Syllabus
  • Useful math formulas
  • Concepts: Uncertainty principle || Operators || Bound and scattering states || Infinite potential well 1D || Wave function 1

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  • Homework 1a
  • Homework 1b
  • Homework 2a
  • Homework 2b
  • Homework 2c* (optional)
  • Homework 2d
  • Homework 3a
  • Homework 3b
  • Homework 4a* (bonus)
• Codes and other links
  Most codes 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 allowed energies in zip format.
  • SHO classically forbidden zones in zip format.
  • SHO with sympy 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.
  • Momentum wf (Gaussian) with sympy in zip format.
  • Finding eigenstates of matrices algebraically with sympy in zip format.
  • Basis transformation and qubits with sympy in zip format.
  • Visualizing and manipulating spherical harmonics in zip format.
  • Spherical Bessel functions and eigenstates of infinite spherical well in zip format.