Homework Help: QM - Wedge-shaped potential - Uncertainty Principle

wombat4000 · Apr 20, 2008

1. The problem statement, all variables and given/known data
See lower down for question

2. Relevant equations

3. The attempt at a solution

I have been trying to find help with this question on the net and in my text books. Im really struggling with QM, i don't know where to start - i appreciate what the graph of the wedge-shaped potential looks like but i just dont understand the rest of it.

wombat4000 · Apr 20, 2008

http://img59.imageshack.us/img59/4688/66098744vb7.th.jpg [Broken]

Astronuc · Apr 20, 2008

Does it mean that one has two conductor plates with the edges close or touching (but well insulated) and the planes form an angle (looking along the planes parallel to the closer for common edges?

Also, please be patient and don't bump with multiple posts.

wombat4000 · Apr 20, 2008

That would make sense i guess.

(Sorry about the multiple posts - i couldnt post the URL without having 15 or more posts.)

wombat4000 · Apr 20, 2008

still no joy though.

Astronuc · Apr 20, 2008

OK, now I get it. I was think an electostatic problem, which this isn't.

I presume one has an idea of what to do if one has a potential V(x).

Well the potential in infinite for x < 0. V(0) = 0, and V(x) = bx, x >0, so it inreases linearly with slope b, i.e. like a ramp function, as opposed to being constant, for example.

It's been 30+ years since I've done this type of calc, so bear with me, and I'll get others to look in.

wombat4000 · Apr 20, 2008

much appreciated.

siddharth · Apr 20, 2008

I think you need to solve the time independent schrodinger equation for this potential, find the stationary state wavefunctions, and then find the standard deviations and variances of the momentum and position