Superposition and the Stern-Gerlach Experiment

Michael Groves
California State University-Fullerton, Chemistry and Biochemistry
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This activity is designed to explore the idea of superposition of basis functions used to describe quantum system using the Stern-Gerlach experiment and light as examples.

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Learning Goals

The goal of the activity is to illustrate how quantum systems are built from a superposition of quantum states. This is illustrated by using the polarization of light. The MATLAB code animates student inputted light polarizations so they can get a sense as to how choosing certain basis sets can explain confusing results from the Stern-Gerlach experiment.

Context for Use

This is meant to be an in-class activity using the provided MATLAB file to animate the results of light polarization experiments. The student won't need much experience with MATLAB, however, they should understand vector notation and have learned about the Stern-Gerlach experiment.

Description and Teaching Materials

Included is activity questions and MATLAB file for students to edit and run.
Superposition Student Handout (Acrobat (PDF) 169kB Aug16 18)
Polarized Light MATLAB File (Matlab File 2kB Aug16 18)

Teaching Notes and Tips

Help students with matrix multiplication will be helpful.


Use an assessment tool like the one outlined in:

References and Resources demonstration video of the Stern-Gerlach experiment: