Question

Shankar: Principles of Quantum Mechanics, 2nd edition, Exercise 17.3.2

Exercise 17.3.2. Consider a spin-1 particle (with no orbital degrees of freedom). Let
H= AS + B(Sx2 — Sy2), where S, are 3 x 3 spin matrices, and A» B. Treating the B term as a
perturbation, find the eigenstates of H° = AS z2 that are stable under the perturbation. Calculate
the energy shifts to first order in B. How are these related to the exact answers?

Answer 1

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