phy-4600/lecture_notes/3-14/3d eigenstates

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❙r❭=❙x,y,z❭
with eigenvalue equations
x̂❙r❭ = x❙r❭
ŷ❙r❭ = y❙r❭
ẑ❙r❭ = z❙r❭
An arbitrary state
❙Ψ❭ = ∫∫∫ dx dy dz ❙x,y,z❭❬x,y,z❙Ψ❭
= ∫ d³r ❙r❭ ❬r❙Ψ❭
Understanding a System:
measure Ĥ, L̂², L̂𝓏 → Constitutes a complete set of commuting observables (except spin)
I.E., There is a set of eigenstates that are eigenstates of all three operators.
Ĥ❙E,l,mₗ❭ = E❙E,l,mₗ❭
L̂²❙E,l,mₗ❭ = l(l+1)ħ²❙E,l,mₗ❭
𝓏❙E,l,mₗ❭ = mₗħ❙E,l,mₗ❭
Ĥ must now include angular momentum
L̂²= (r̂×p̂)(r̂×p̂) = (geometric identity) = r̂²p̂ - (r̂⋅p̂) + ιħr̂⋅p̂