Qbits

• Classical bit

  • 2 discrete values (0 or 1)
  • Values are independent

• Qbit

  • Continuum of values in 2 basis vectors
  • Values are not independent

• Qbit is {a?0? + b?1?}

  • a and b are probability amplitudes
  • Measurement ? get zero or one
    • Nonlinear, irreversible operation
    • Collapse the state to the poles
    • Probabilities sum to 1
  • Entire sphere is available if we don’t observe the state

Bloch sphere: A visualization tool

• Spin up and down correspond to N and S

Previous slide

Next slide

Back to first slide

View graphic version