# What's fundamental for quantum mechanics?

1. Jul 19, 2013

### SamRoss

As I understand it, a lot of what is taught about quantum mechanics are special techniques for solving problems. I'm not a physicist, so something like perturbation theory is not what I'm after. To be more specific, i would like to know the minimum that is necessary for "doing" quantum mechanics, regardless of how inefficient it would be to apply these minimal techniques to complex problems (because as a non-physicist I will never have to work out a complex problem).

What I have learned so far is that the Schrodinger equation is not enough because it does not take spin into account. I think the Schrodinger-Pauli and Dirac equations do. Are there any other equations I should look up? Are knowing the equations and how to apply Hamiltonians all that is really necessary for working out any QM problem (regardless of how time-consuming it would be)?

Last edited: Jul 19, 2013
2. Jul 19, 2013

The "minimum" would depend on what kind of problem(s) you are interested in. The great divide in applied QM is between solid state (including surface) applications and molecular (including cluster) applications.

3. Jul 20, 2013

### fargoth

Why is the non-existence of spin in the equation a deal breaker for you, while the non-relativistic nature of these equations is not?

As gadong have said, it all depends on the problem.

Using first quantization would not permit calculations involving creation and annihilation of particles.

4. Jul 20, 2013

### tom.stoer

Understanding quantum mechanics requires linear algebra, (partial) differential equations, and some very basic knowledge in functional analysis (which appears as a kind of infinite-dimensional generalization of linear algebra).

5. Jul 20, 2013

### Demystifier

This may help:
https://www.physicsforums.com/blog.php?b=3873 [Broken]

Last edited by a moderator: May 6, 2017
6. Jul 20, 2013

### SamRoss

I was not aware that they were not relativistic. Thanks for the heads up.