Small Group Activity: Changing Spin Bases with a Completeness Relation

Quantum Fundamentals 2021
Students work in small groups to use completeness relations to change the basis of quantum states.
  1. Imagine a spin-1/2 system prepared in the state:

    \[\left|{\psi}\right\rangle = \sqrt{\frac{2}{5}} \left|{+}\right\rangle + i\sqrt{\frac{3}{5}} \left|{-}\right\rangle \]

    Use a completeness relation to write this state in the \(S_x\) basis.

  2. Use a completeness relation to write \(\left|{-}\right\rangle \) in the \(S_y\) basis.

Keywords
Completeness Relations Quantum States
Learning Outcomes