In: Physics
(4) Consider a system described by the Hamiltonian H, H = 0 a a
0 !,
where a is a constant. (a) At t = 0, we measure the energy of the
system, what possible values will we obtain? (b) At later time t,
we measure the energy again, how is it related to its value we
obtain at t = 0 ? (c) If at t = 0, the system is equally likely to
be in its two possible states, write down the most general state of
the system at t = 0. (d) What is the probability that at time t =
5, the system will be in a state different from its initial state?.
(e) Suppose the above Hamiltonian describes a spin-1/2 particle in
a magnetic field. If Sx is found to be ¯h/2, what is the probability
of getting Sz equal to ¯h/2?. What is the probability of getting Sy
equal to −¯h/2 ? What is the probability of getting Sx equal to
−¯h/2
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