130_notes.dvi

(Frankie) #1

  1. A hydrogen atom is in an eigenstate (ψ) ofJ^2 ,L^2 , and ofJz such thatJ^2 ψ =^154 ̄h^2 ψ,
    L^2 ψ= 6 ̄h^2 ψ,Jzψ=−^12 ̄hψ, and of course the electron’s spin is^12. Determine the quantum
    numbers of this state as well as you can. If a measurement ofLzis made, what are the possible
    outcomes and what are the probabilities of each.

  2. A hydrogen atom is in the stateψ=R 32 Y 21 χ−. If a measurement ofJ^2 and ofJzis made,
    what are the possible outcomes of this measurement and what are the probabilities for each
    outcome? If a measurement of the energy of the state is made, what are the possible energies
    and the probabilities of each? You may ignore the nuclear spin in this problem.

  3. Two identical spin 1 particles are bound together into a state withorbital angular momentum
    l. What are the allowed states of total spin (s) forl= 2, forl= 1, and forl= 0? List all
    the allowed states giving, for each state, the values of the quantum numbers for total angular
    momentum (j), orbital angular momentum (l) and spin angular momentum (s) iflis 2 or less.
    You need not list all the differentmjvalues.

  4. List all the allowed states of total spin and total z-component of spin for 2 identical spin 1
    particles. Whatℓvalues are allowed for each of these states? Explicitly write down the(2s+1)
    states for the highestsin terms ofχ(1)+,χ(2)+,χ(1) 0 ,χ(2) 0 ,χ(1)−, andχ(2)−.

  5. Two different spin^12 particles have a Hamiltonian given byH=E 0 + ̄hA 2 S~ 1 ·S~ 2 +B ̄h(S 1 z+S 2 z).
    Find the allowed energies and the energy eigenstates in terms of thefour basis states|+ +〉,
    |+−〉,|−+〉, and|−−〉.

  6. A spin 1 particle is in anℓ= 2 state. Find the allowed values of the total angular momentum
    quantum number,j. Write out the|j,mj〉states for the largest allowedjvalue, in terms of
    the|ml,ms〉basis. (That is give one state for everymjvalue.) If the particle is prepared in
    the state|ml= 0,ms= 0〉, what is the probability to measureJ^2 = 12 ̄h^2?

  7. Two different spin 21 particles have a Hamiltonian given byH=E 0 +AS~ 1 ·S~ 2 +B(S 1 z+S 2 z).
    Find the allowed energies and the energy eigenstates in terms of thefour product states
    χ(1)+χ(2)+,χ(1)+χ(2)−,χ(1)−χ(2)+, andχ(1)−χ(2)−.

Free download pdf