posted by quant .
8d. Now suppose we start with the qubit |ø(0)⟩=|0⟩ and we apply a magnetic field in the x^ direction at t=0. This corresponds to the Hamiltonian H=BX, where B is a constant and X is the usual bit flip gate. What are the coordinates (è,ϕ) of this qubit on the Bloch sphere at time t, as a function of B and t?
urgent help please...