Fermi · Concept Library · Courses · Books · Problems · Simulations · Math Wiki · High School Fermi › Problems A Modern Approach to Quantum Mechanics · Problem 1.11
Rotation of Basis States and Matrix Mechanics — John S. Townsend
Physics — Quantum Mechanics · spin-state-expectation-values-compare
Problem Calculate ⟨ S x ⟩ \langle S_x\rangle ⟨ S x ⟩ ⟨ S y ⟩ \langle S_y\rangle ⟨ S y ⟩ ⟨ S z ⟩ \langle S_z\rangle ⟨ S z ⟩ ∣ ψ ⟩ = − i 2 ∣ + z ⟩ + 3 2 ∣ − z ⟩ |\psi\rangle = -\frac{i}{2}|{+}\mathbf{z}\rangle + \frac{\sqrt{3}}{2}|{-}\mathbf{z}\rangle ∣ ψ ⟩ = − 2 i ∣ + z ⟩ + 2 3 ∣ − z ⟩ Browse the problem library