PROBLEM (10 Points) The azimuthal wave function for the hydrogen atom
can be obtained from the solution of the azimuthal component of the Schrodinger
equation as follows
Φ(φ) = Αρίηφ
where φ∈ [0,2π) is the angle around z-axis in spherical coordinates as shown
in the figure and A is the normalization constant.
(a) [3 Points] Find the allowed values of m from the periodicity condition Φ(φ) = Φ(φ+2π) and the normalization
constant A from ∫0^2π dφ |Φ(φ)|^2 = 1.
(b) [4 Points] Find the operator L₂ in spherical coordinates where full angular momentum vector is given by
the operator
L = r x p.
Note that in spherical coordinates r = rî and p = -iħ∇ with ∇ = ∂/∂r + 1/r ∂/∂θ + 1/(rsinθ) ∂/∂φ and unit vectors form
an orthogonal system with the cross products θ̂ x φ̂ = r̂ and cyclic permutation of θ̂, φ̂, r̂. (Hint: Consider the
dot product L₂ = ẑ · L where unit vector along z can be written in spherical coordinates ẑ = cos θ θ̂ - sin θ φ̂.)
(c) [3 Points] Find the expectation value of L₂ using your results in (a) and (b).