1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Quantum Computation Magnetic Spin

  1. Oct 17, 2013 #1
    1. The problem statement, all variables and given/known data
    A qubit is in the state |ψ(0)>=|0> . A magnetic field is applied 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 (θ,ϕ) of this qubit on the Bloch sphere at time t, as a function of B and t?


    2. Relevant equations

    I think i have to introduce e^(-i*H*t) into the qubit state.
    The generic form of |ψ (t)> = cos(θ/2)|0> + (e^(iϕ))*sin(θ/2)|1>

    3. The attempt at a solution
    I have followed this through and have got θ = ∏ and ϕ = B*t
    However looking at the Bloch sphere it would seem that theta is ∏/2. Also from the diagram i would think that ϕ would be 0 or 2BT but i am not sure.
     
  2. jcsd
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?



Similar Discussions: Quantum Computation Magnetic Spin
Loading...