Is ψ(x) = a0exp(-βx²) an Eigenfunction of the Hamiltonian?

Click For Summary

Homework Help Overview

The discussion revolves around the question of whether the function ψ(x) = a0exp(-βx²) is an eigenfunction of the Hamiltonian for a particle in a one-dimensional potential V(x) = 1/2(mω²x²). Participants are tasked with showing this relationship for a suitable value of β and calculating the corresponding energy E1.

Discussion Character

  • Exploratory, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants describe their attempts to differentiate the function ψ(x) and substitute it into the Hamiltonian. There are questions about the steps taken in the differentiation process and the implications of setting the Hamiltonian to zero. Some participants seek clarification on how the x² terms cancel out and the determination of the specific value of β.

Discussion Status

The discussion is ongoing, with participants sharing their attempts and seeking further explanations. There is a recognition that a specific value of β is necessary for ψ(x) to be an eigenfunction, but no consensus has been reached on the differentiation process or the resulting expressions.

Contextual Notes

Participants note potential confusion regarding the differentiation of the wave function and the application of the Hamiltonian. There are indications of missing terms in the calculations, and some participants reference external solutions that may not be fully understood.

phys2
Messages
21
Reaction score
0

Homework Statement



A particle moves in a one dimensional potential : V(x) = 1/2(mω2x

Show that the function ψ(x) = a0exp(-βx2) is an eigenfunction for the Hamiltonian for a suitable value of β and calculate the value of energy E1

Homework Equations





The Attempt at a Solution



What I did was take the Hamiltonian, differentiate twice the function ψ(x) and then sub in the twice differentiated function along with the potential into the Hamiltonian. But there I get confused. Apparently taking a peek at the solutions, it argues that you should set the Hamiltonian to zero and then since it is supposed to be a constant, the x^2 terms cancel out and your final answer is β=mω/2hbar. I have no idea what they have done though! Any one care to explain? Thanks!
 
Physics news on Phys.org
phys2 said:

Homework Statement



A particle moves in a one dimensional potential : V(x) = 1/2(mω2x

Show that the function ψ(x) = a0exp(-βx2) is an eigenfunction for the Hamiltonian for a suitable value of β and calculate the value of energy E1

Homework Equations





The Attempt at a Solution



What I did was take the Hamiltonian, differentiate twice the function ψ(x) and then sub in the twice differentiated function along with the potential into the Hamiltonian.
Show us what you got when you did that. If ##\psi## is an eigenfunction of ##\hat{H}##, what does ##\hat{H}\psi## have to equal?

But there I get confused. Apparently taking a peek at the solutions, it argues that you should set the Hamiltonian to zero and then since it is supposed to be a constant, the x^2 terms cancel out and your final answer is β=mω/2hbar. I have no idea what they have done though! Any one care to explain? Thanks!
 
So I got -h(bar)2/2m (4β2x2) ψ + 1/2mω2x2ψ = Hamiltonian

Hψ=Eψ?
 
phys2 said:
So I got -h(bar)2/2m (4β2x2) ψ + 1/2mω2x2ψ = Hamiltonian
You're missing a term. You didn't differentiate correctly, perhaps.

Hψ=Eψ?
Right, so after applying the Hamiltonian, you should be able to write the result as a constant times the original wave function. To do that, β will have to take on a specific value.
 

Similar threads

  • · Replies 1 ·
Replies
1
Views
2K
Replies
5
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 22 ·
Replies
22
Views
3K
Replies
6
Views
2K
Replies
9
Views
2K
Replies
2
Views
3K
Replies
1
Views
2K