- #1
Xyius
- 508
- 4
Homework Statement
In a spherical well in which..
[tex]V=
\begin{cases}
0,\text{for }0 \le r < R \\
∞, \text{for } r > R
\end{cases}
[/tex]
the s-wave eigenstates are
[tex]\phi_n(r)=\frac{A}{r}\sin\left( \frac{n\pi r}{R} \right)[/tex]
where A is a normalization constant. If a particle is in the ground state and R suddenly
increases to ##R'=R/\epsilon##, where ##0 \le \epsilon \le 1##
(i) Compute and plot the probability of finding the particle in the new ground state as a
function of ##\epsilon##.
(ii) Compute and plot the probability of finding the particle in a new state with quantum
number n as a function of ##\epsilon## and n (this will be a 3D plot). What are the most important
features you see in your plot?
(iii) Sum all probabilities in (ii) for = 1=2 to show that they add to 1.
Note: The relations
[tex]\sum_{n=0}^{∞}\frac{1}{(2n+1)^2}=\frac{\pi^2}{8}[/tex]
[tex]\sum_{n=0}^{∞}\frac{1}{(2n+3)^2(2n-1)^2}=\frac{\pi^2}{64}[/tex]
may be useful here.
Homework Equations
Obviously the ones given in the problem.
Also, this problem deals with the sudden approximation. Which says that when the system is changed very rapidly, the state remains unchanged initially and then is allowed to evolve.
The Attempt at a Solution
My solution is in the attached images. I know typing it out would have been ideal but it would have been too much and I could give more of my work this way. I scanned them to make sure they were high quality images.
I don't know where my thought process went wrong, but what I am getting for part (iii) is obviously wrong since it diverges at n=2.