The ground state of hydrogen is perturbed by a (time-independent) uniform electric field E=E0z^, but now the perturbation is suddenly turned off at time T. Using the results of Chapter 7 for time-independent perturbation theory:
(a) What is the wave function at t=0+ (just after the field is turned on)?
(b) What is the wave function at time T− (just before the field is turned off)?
(c) What is the wave function at time T+ (just after the field is turned off)?
(d) What is the probability that the atom is found in state ∣2,1,0⟩ at time T+?