QM · Ch 4 · Spin-1/2: ⟨S_x⟩ and ⟨S_x²⟩ in |↑⟩

Physics · Quantum Mechanics · Griffiths Ch 4

Problem

A spin-1/2 particle is in the state

|\uparrow\rangle

(eigenstate of

S_z

with eigenvalue

+\hbar/2

). Compute

\langle S_x \rangle

and

\langle S_x^2 \rangle