IGNOU MPH 4 2026 - Derive the Heisenberg equations of motion for and &nbs

Question

Derive the Heisenberg equations of motion for $\hat{S}_x$ and $\hat{S}_y$ for the Hamiltonian $\hat{H} = \omega\hat{S}_z$ .

19 Jan 2026

Answer :

Word Count : 134

In the Heisenberg picture the time evolution of an operator (\hat A) with no explicit time dependence is given by [ \frac{d\hat A}{dt}=\frac{i}{\hbar}[\hat H,\hat A]. ] The Hamiltonian is (\hat H=\omega \hat S_z). Using the angular momentum commutation relations [

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