Degeneracy of hydrogen with infinite potential wall on one side

Join the discussion
Registration is free. Start your own thread to ask a follow-up.
1 reply · 3K views
Silicon-Based
Messages
51
Reaction score
1
Homework Statement
Find the energy degeneracy of a hydrogen atom with infinite potential barrier
Relevant Equations
##|m| \leq l < n##
##P = (-1)^l##
I'm considering a hydrogen atom placed in an infinite potential on one side of the nucleus, i.e. ##V(x) = +\infty## for ##x < 0##. I require the wavefunctions to be odd in order to satisfy the boundary condition at ##x=0##. By parity of the spherical harmonics only states with ##l## odd are allowed, so the ground state and first excited state should respectively have ##n=2## and ##n=4##. Since even ##l## are excluded, the number of possible values of ##l## is ##\lfloor{n/2}\rfloor##, so the degeneracy is:

$$
g_n = \sum_{l=1,\, l \,\text{odd}}^{n-1 \, (n\, \text{even}),\,n-2 \, (n \,\text{odd})} (2l+1) = \lfloor{n/2}\rfloor(\lfloor{n/2}\rfloor+1)
$$

Is my reasoning above correct? Is it reasonable to assume that the energy eigenvalues have the same form as for the usual hydrogen atom?
 
Physics news on Phys.org
Yes. The differential equation is same as original Hydrogen atom problem with the restriction. As you have correctly determined only odd values are the solutions so as to satisfy boundary conditions. The degeneracy is now over those restricted ##l##
 
  • Like
Likes   Reactions: Silicon-Based