Expectation values for a harmonic oscillator

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Homework Help Overview

The discussion revolves around calculating expectation values for a particle in the first state of a harmonic oscillator, specifically , ,

, and . The original poster presents the wave function and the method for finding these values using integral definitions.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to determine the operators for and after successfully finding . Some participants confirm the use of x² as the operator for and provide the integral form for .

Discussion Status

The discussion is ongoing, with participants providing clarifications on the operators needed for the calculations. There is a supportive atmosphere as the original poster expresses appreciation for the assistance received.

Contextual Notes

The original poster mentions challenges with LaTeX formatting, indicating potential confusion in presenting mathematical expressions clearly.

KaiserBrandon
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Homework Statement


I need to find <x>, <x2>, <p>, and <p2> for a particle in the first state of a harmonic oscillator.


Homework Equations


The harmonic oscillator in the first state is described by [tex]\psi[/tex](x)=A[tex]\alpha[/tex]1/2*x*e-[tex]\alpha[/tex]*x2/2. I'm using the definition <Q>=([tex]\int[/tex][tex]\psi[/tex]1*Q*[tex]\psi[/tex])dx where [tex]\psi[/tex]1 is the complex conjugate of [tex]\psi[/tex], and Q is the specific operator.


The Attempt at a Solution


I solved for <x>, and found it was zero. <p> I'll solve for in a similar fashion. However, for <x2> and <p2>, I am unsure of what operators I use. For the <x> operator, it is simply x, so for <x2>, would I use x2 as an operator?
(note that I the only superscripts here are the ones above e, I don't know why latex is putting all of my symbols so high
 
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KaiserBrandon said:
For the <x> operator, it is simply x, so for <x2>, would I use x2 as an operator?

Yes, that's what you should use.
 
(Put the whole equation in the tex barackets instead of individual symbols)

The operator for <x²> is simply multiplication by x², so <x²> = ∫ψ*(x)x²ψ(x)dx, and <p²> is

[tex]-\int \psi^{*}(x) \hbar^2\frac{\partial^2}{\partial x^2}\psi(x) dx[/tex]
 
ok, thank you so much guys. It's a good thing I have physics forum to at least make my new ventures into the realm of quantum mechanics a bit easier :)
 

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