Second solution: Instead of using operator algebra, we can find a wave
function in the momentum representation, whereThe Hamiltonian then isThe Schrödinger equation for becomesThis equation has exactly the same form as the standard oscillator
Schrödingerequation:We then obtain for the momentum probability distribution for the ground
state:
Therefore
where Using the old “differentiate with respect to an
innocent parameter method” of simplifying an integral, we may rewrite
as
where we substituted (S.5.44.10) into (S.5.44.11) and let Fi-
nally,
QUANTUM MECHANICS 295