A Modern Approach to Quantum Mechanics · Problem 2.5

Angular Momentum — John S. Townsend

Physics — Quantum Mechanics · matrix-representation-jz-sy-basis

Problem

What is the matrix representation of

\hat{J}_z

using the states

|{+y}\rangle

and

|{-y}\rangle

as a basis? Use this representation to evaluate the expectation value of

S_z

for a collection of particles each in the state

|{-y}\rangle