A Modern Approach to Quantum Mechanics · Problem 2.11

Angular Momentum — John S. Townsend

Physics — Quantum Mechanics · expectation-value-sx-matrix-mechanics

Problem

The column vector representing the state

|\psi\rangle

is given by

|\psi\rangle \xrightarrow{S_z\text{ basis}} \frac{1}{\sqrt{3}}\begin{pmatrix} 1 \\ \sqrt{2} \end{pmatrix}

Use matrix mechanics and the result of Problem 2.10 to determine

\langle S_x\rangle

for this state.