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JayKo
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Homework Statement
Consider a quantum particle of mass m in a 3-D harnonic potential with frequency [itex]\omega[/itex] and it experiences a perturbation [itex]H_{1}=az^{2}[/itex]
a. Determine the effect of [tex]H_{1}[/tex] on the 1st exicted level of the system ( at the 1st order perturbation)
b. what happen to L[tex]^{2}[/tex] and [tex]L_{z}[/tex]? are they still conserved in presence of [tex]H_{1}[/tex]?
Homework Equations
1st order : [itex]E^{(1)}=<\Psi|H_{1}|\Psi[/itex]>
The Attempt at a Solution
Subsititute in the perturb into the energy equation.
[itex]E^{(1)}=<\Psi|az^{2}|\Psi[/itex]>
1st excited state is [itex]|\Psi_{112}[/itex]>, [itex]|\Psi_{121}[/itex]>, [itex]|\Psi_{211}[/itex]>
then find the value of <[itex]\Psi_{112}|az^{2}||\Psi_{112}[/itex]>, <[itex]\Psi_{121}|az^{2}||\Psi_{121}[/itex]>,
<[itex]\Psi_{211}|az^{2}||\Psi_{211}[/itex]>, susb [itex]z^{2}=r^{2}-x^{2}-y^{2}[/itex]
and [itex]x^{2}=\frac{\hbar}{2m\omega}[a^{2}_{+}+a_{+}a_{-}+a_{-}a_{+}+a^{2}_{-}][/itex]
but i don't know what is the representation for [itex]y^{2} and r^{2}[/itex]
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