Materials are presented here in an order appropriate for
an upper level undergraduate course in Quantum Mechanics.
The activities in this sequence are meant to draw from
standard prerequisites to such a course, such as pendulum
motion and wave motion on a string. Review activities
on eigenvalues (using pendulum motion) and standing waves
on strings might be used individually with students not yet
prepared for quantum mechanics.
In addition, while the mathematics involved in the solution
to Schrodinger's equation can be difficult even for a problem
which has a solution, such as the Hydrogen atom, the solution
to the radial problem may prove the easier of the two to introduce
to students in a numerical manner, particularly in that the
boundary conditions are more physically intuitive. It may be useful for
some classes to skip the angular solution, and simply use the known
solution for the purposes of visualization.
Introducing students to eigenvalue problems in physics
It should be stressed to the students the meaning of an eigenvalue
problem as typically used in physics. While there are mathematically
rigorous definitions of the problem in terms of matrix operations, in
science it is often used more loosely to describe problems for which
there are some finite number of possible solutions that satisfy either
boundary conditions or other constraints. It is often described to the
student that the particle exists in a superposition of all solutions
of Schrodinger's equation, but we do not accept any solution, but
rather those that satisfy reasonable boundary conditions. We enforce
that a particle bound within some potential be less likely to be found
as we move into regions of higher potential. We enforce that the
electron's most likely position should not be in the nucleus. Those
specific solutions that meet these criteria are the solutions we keep.
It should also be stressed to students that there is no single
foolproof method for finding eigenvalues, and that they should be
prepared to address these problems with a variety of techniques.