Principles of Quantum Mechanics · Problem 14.3.7

Spin — R. Shankar

Physics — Quantum Mechanics · pauli-matrix-linear-combinations

Problem

Express the following as linear combinations of the Pauli matrices and

I

: (1)

(I + i\sigma_x)^{1/2}

. (Relate it to half a certain rotation.) (2)

(2I + \sigma_x)^{-1}

. (3)

\sigma_x^{-1}