Raising Operator (Harmonic Oscillator)

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SUMMARY

The discussion focuses on the application of the raising operator for the harmonic oscillator's ground state wavefunction, represented as $\chi_0 = \left( \frac{\alpha}{\pi} \right)^{\frac{1}{4}} \exp\left(-\frac{\alpha x^2}{2}\right)$, where $\alpha = \sqrt{\frac{mk}{\hbar^2}}$. The user seeks clarification on the correct application of the raising operator, defined as $\frac{d}{dy} - y$, with the substitution $y = \sqrt{\alpha} x$. They express confusion regarding the transformation of variables and the expected outcomes when applying both the raising and lowering operators. The user also questions the significance of the results obtained, particularly in relation to the first excited state.

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heardie
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This is (another!) question I cannot solve
The ground state wavefunction for the harmonic oscillator can be written as
$\chi _0 = \left( {\frac{\alpha }<br /> {\pi }} \right)^{\frac{1}<br /> {4}} \exp \left( {\frac{{ - \alpha x^2 }}<br /> {2}} \right)$<br />

where $\alpha = \sqrt {\frac{{mk}}<br /> {{\hbar ^2 }}} $<br />

We are then asked to apply the rasing operator:
d/dy-y

where $y = \sqrt \alpha x$<br />
First of all, does this mean replace all alphas, and x's with y's? (Is it even possible to get rid of all x's? I end up with a y/x in there), and then apply
d(chi)/dy-y*chi
Is that what the operator is doing? I don't see the significane of the answer. If I apply the lowering operator (d/dy + y) I still get 'an' answer, when I figure I should get something to tell me I can't go lower then the groud state (a zero perhaps, or a mathematical impossibility like division by zero)

Anyway...if anyone can shed some light on this it would eb much appreciated!

Edit: I can't figure out division on this board! I swear to god I am doing it right...I will post my operator down here...if someone can point out the latex error I'd love to know:
\[<br /> \frac{d}<br /> {{dy}} - y<br /> \]<br /> <br />
 
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I swear my equations are printing in the wrong order above. For reference:
Raising operator - d/dy - y
where y = sqrt(alpha)*x

Oh and I get
-1/2\,{\frac {{e^{-1/2\,\alpha\,{x}^{2}}} \left( -1+4\,\alpha\,{x}^{2}<br /> \right) }{x\sqrt [4]{\alpha\,\pi }}}<br />

Is this the first excited state? Pretty sure I would have made an error somewhere there!
 
Dont worry. Completly missed something here. All makes sesnse now. Can I delete this thread somehow?
 

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